drm/amdgpu/pm: Fix the null pointer dereference for smu7

optimize the code to avoid pass a null pointer (hwmgr->backend)
to function smu7_update_edc_leakage_table.
Signed-off-by: Ma Jun <Jun.Ma2@amd.com>
Reviewed-by: Yang Wang <kevinyang.wang@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/pm/powerplay/hwmgr/smu7_hwmgr.c

@@ -2957,6 +2957,7 @@ static int smu7_update_edc_leakage_table(struct pp_hwmgr *hwmgr)
 
 static int smu7_hwmgr_backend_init(struct pp_hwmgr *hwmgr)
 {
+	struct amdgpu_device *adev = hwmgr->adev;
 	struct smu7_hwmgr *data;
 	int result = 0;
 
@@ -2993,40 +2994,37 @@ static int smu7_hwmgr_backend_init(struct pp_hwmgr *hwmgr)
 	/* Initalize Dynamic State Adjustment Rule Settings */
 	result = phm_initializa_dynamic_state_adjustment_rule_settings(hwmgr);
 
-	if (0 == result) {
-		struct amdgpu_device *adev = hwmgr->adev;
+	if (result)
+		goto fail;
 
-		data->is_tlu_enabled = false;
+	data->is_tlu_enabled = false;
 
-		hwmgr->platform_descriptor.hardwareActivityPerformanceLevels =
+	hwmgr->platform_descriptor.hardwareActivityPerformanceLevels =
 							SMU7_MAX_HARDWARE_POWERLEVELS;
-		hwmgr->platform_descriptor.hardwarePerformanceLevels = 2;
-		hwmgr->platform_descriptor.minimumClocksReductionPercentage = 50;
+	hwmgr->platform_descriptor.hardwarePerformanceLevels = 2;
+	hwmgr->platform_descriptor.minimumClocksReductionPercentage = 50;
 
-		data->pcie_gen_cap = adev->pm.pcie_gen_mask;
-		if (data->pcie_gen_cap & CAIL_PCIE_LINK_SPEED_SUPPORT_GEN3)
-			data->pcie_spc_cap = 20;
-		else
-			data->pcie_spc_cap = 16;
-		data->pcie_lane_cap = adev->pm.pcie_mlw_mask;
-
-		hwmgr->platform_descriptor.vbiosInterruptId = 0x20000400; /* IRQ_SOURCE1_SW_INT */
-/* The true clock step depends on the frequency, typically 4.5 or 9 MHz. Here we use 5. */
-		hwmgr->platform_descriptor.clockStep.engineClock = 500;
-		hwmgr->platform_descriptor.clockStep.memoryClock = 500;
-		smu7_thermal_parameter_init(hwmgr);
-	} else {
-		/* Ignore return value in here, we are cleaning up a mess. */
-		smu7_hwmgr_backend_fini(hwmgr);
-	}
+	data->pcie_gen_cap = adev->pm.pcie_gen_mask;
+	if (data->pcie_gen_cap & CAIL_PCIE_LINK_SPEED_SUPPORT_GEN3)
+		data->pcie_spc_cap = 20;
+	else
+		data->pcie_spc_cap = 16;
+	data->pcie_lane_cap = adev->pm.pcie_mlw_mask;
+
+	hwmgr->platform_descriptor.vbiosInterruptId = 0x20000400; /* IRQ_SOURCE1_SW_INT */
+	/* The true clock step depends on the frequency, typically 4.5 or 9 MHz. Here we use 5. */
+	hwmgr->platform_descriptor.clockStep.engineClock = 500;
+	hwmgr->platform_descriptor.clockStep.memoryClock = 500;
+	smu7_thermal_parameter_init(hwmgr);
 
 	result = smu7_update_edc_leakage_table(hwmgr);
-	if (result) {
-		smu7_hwmgr_backend_fini(hwmgr);
-		return result;
-	}
+	if (result)
+		goto fail;
 
 	return 0;
+fail:
+	smu7_hwmgr_backend_fini(hwmgr);
+	return result;
 }
 
 static int smu7_force_dpm_highest(struct pp_hwmgr *hwmgr)