drm/amdgpu: Drop unnecessary return statements

There is no reason to call return at the end of function that
returns void.

Fixes the below:

WARNING: void function return statements are not generally useful

Thus remove such a statement in the affected functions.

Cc: Christian König <christian.koenig@amd.com>
Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: "Pan, Xinhui" <Xinhui.Pan@amd.com>
Signed-off-by: Srinivasan Shanmugam <srinivasan.shanmugam@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/amdgpu/amdgpu_res_cursor.h

@@ -112,7 +112,6 @@ static inline void amdgpu_res_first(struct ttm_resource *res,
 	cur->remaining = size;
 	cur->node = NULL;
 	WARN_ON(res && start + size > res->size);
-	return;
 }
 
 /**

drivers/gpu/drm/amd/amdgpu/atombios_encoders.c

@@ -228,7 +228,6 @@ void amdgpu_atombios_encoder_init_backlight(struct amdgpu_encoder *amdgpu_encode
 register_acpi_backlight:
 	/* Try registering an ACPI video backlight device instead. */
 	acpi_video_register_backlight();
-	return;
 }
 
 void

drivers/gpu/drm/amd/amdgpu/gfx_v9_4_2.c

@@ -746,8 +746,6 @@ void gfx_v9_4_2_init_golden_registers(struct amdgpu_device *adev,
 			 die_id);
 		break;
 	}
-
-	return;
 }
 
 void gfx_v9_4_2_debug_trap_config_init(struct amdgpu_device *adev,

drivers/gpu/drm/amd/amdgpu/ih_v6_0.c

@@ -641,8 +641,6 @@ static void ih_v6_0_update_clockgating_state(struct amdgpu_device *adev,
 		if (def != data)
 			WREG32_SOC15(OSSSYS, 0, regIH_CLK_CTRL, data);
 	}
-
-	return;
 }
 
 static int ih_v6_0_set_clockgating_state(void *handle,
@@ -726,8 +724,6 @@ static void ih_v6_0_get_clockgating_state(void *handle, u64 *flags)
 
 	if (!RREG32_SOC15(OSSSYS, 0, regIH_CLK_CTRL))
 		*flags |= AMD_CG_SUPPORT_IH_CG;
-
-	return;
 }
 
 static const struct amd_ip_funcs ih_v6_0_ip_funcs = {

drivers/gpu/drm/amd/amdgpu/navi10_ih.c

@@ -665,8 +665,6 @@ static void navi10_ih_update_clockgating_state(struct amdgpu_device *adev,
 		if (def != data)
 			WREG32_SOC15(OSSSYS, 0, mmIH_CLK_CTRL, data);
 	}
-
-	return;
 }
 
 static int navi10_ih_set_clockgating_state(void *handle,
@@ -691,8 +689,6 @@ static void navi10_ih_get_clockgating_state(void *handle, u64 *flags)
 
 	if (!RREG32_SOC15(OSSSYS, 0, mmIH_CLK_CTRL))
 		*flags |= AMD_CG_SUPPORT_IH_CG;
-
-	return;
 }
 
 static const struct amd_ip_funcs navi10_ih_ip_funcs = {

drivers/gpu/drm/amd/amdgpu/nbio_v7_9.c

@@ -173,8 +173,6 @@ static void nbio_v7_9_sdma_doorbell_range(struct amdgpu_device *adev, int instan
 	default:
 		break;
 	}
-
-	return;
 }
 
 static void nbio_v7_9_vcn_doorbell_range(struct amdgpu_device *adev, bool use_doorbell,
@@ -556,7 +554,6 @@ const struct amdgpu_nbio_funcs nbio_v7_9_funcs = {
 static void nbio_v7_9_query_ras_error_count(struct amdgpu_device *adev,
 					void *ras_error_status)
 {
-	return;
 }
 
 static void nbio_v7_9_handle_ras_controller_intr_no_bifring(struct amdgpu_device *adev)

drivers/gpu/drm/amd/amdgpu/nv.c

@@ -1115,8 +1115,6 @@ static void nv_common_get_clockgating_state(void *handle, u64 *flags)
 	adev->hdp.funcs->get_clock_gating_state(adev, flags);
 
 	adev->smuio.funcs->get_clock_gating_state(adev, flags);
-
-	return;
 }
 
 static const struct amd_ip_funcs nv_common_ip_funcs = {

drivers/gpu/drm/amd/amdgpu/soc21.c

@@ -885,8 +885,6 @@ static void soc21_common_get_clockgating_state(void *handle, u64 *flags)
 	adev->nbio.funcs->get_clockgating_state(adev, flags);
 
 	adev->hdp.funcs->get_clock_gating_state(adev, flags);
-
-	return;
 }
 
 static const struct amd_ip_funcs soc21_common_ip_funcs = {

drivers/gpu/drm/amd/amdgpu/vcn_v4_0.c

@@ -877,8 +877,6 @@ static void vcn_v4_0_enable_clock_gating(struct amdgpu_device *adev, int inst)
 		| UVD_SUVD_CGC_CTRL__IME_MODE_MASK
 		| UVD_SUVD_CGC_CTRL__SITE_MODE_MASK);
 	WREG32_SOC15(VCN, inst, regUVD_SUVD_CGC_CTRL, data);
-
-	return;
 }
 
 static void vcn_v4_0_enable_ras(struct amdgpu_device *adev, int inst_idx,