drm/amd/pm: add missing error handling in function smu_v13_0_6_allocate_dpm_context

Check return value to avoid null pointer dereference.
Signed-off-by: Bob Zhou <bob.zhou@amd.com>
Reviewed-by: Yang Wang <kevinyang.wang@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/pm/swsmu/smu13/smu_v13_0_6_ppt.c

@@ -451,6 +451,11 @@ static int smu_v13_0_6_allocate_dpm_context(struct smu_context *smu)
 
 	smu_dpm->dpm_policies =
 		kzalloc(sizeof(struct smu_dpm_policy_ctxt), GFP_KERNEL);
+	if (!smu_dpm->dpm_policies) {
+		kfree(smu_dpm->dpm_context);
+		return -ENOMEM;
+	}
+
 	if (!(smu->adev->flags & AMD_IS_APU)) {
 		policy = &(smu_dpm->dpm_policies->policies[0]);