drivers/amd/pm: check the return value of amdgpu_bo_kmap

amdgpu_bo_kmap() returns error when fails to map buffer object. Add the
error check and propagate the error.
Signed-off-by: Li Zhong <floridsleeves@gmail.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/pm/legacy-dpm/kv_dpm.c

@@ -1384,13 +1384,16 @@ static int kv_dpm_enable(struct amdgpu_device *adev)
 static void kv_dpm_disable(struct amdgpu_device *adev)
 {
 	struct kv_power_info *pi = kv_get_pi(adev);
+	int err;
 
 	amdgpu_irq_put(adev, &adev->pm.dpm.thermal.irq,
 		       AMDGPU_THERMAL_IRQ_LOW_TO_HIGH);
 	amdgpu_irq_put(adev, &adev->pm.dpm.thermal.irq,
 		       AMDGPU_THERMAL_IRQ_HIGH_TO_LOW);
 
-	amdgpu_kv_smc_bapm_enable(adev, false);
+	err = amdgpu_kv_smc_bapm_enable(adev, false);
+	if (err)
+		DRM_ERROR("amdgpu_kv_smc_bapm_enable failed\n");
 
 	if (adev->asic_type == CHIP_MULLINS)
 		kv_enable_nb_dpm(adev, false);