drm/amdgpu/powerplay/vega10: fix memory leak in error path

Free the backend structure if we fail to allocate device
memory.

Reviewed-by: Evan Quan <evan.quan@amd.com>
Reviewed-by: Rex Zhu <Rex.Zhu@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/powerplay/smumgr/vega10_smumgr.c

@@ -406,9 +406,8 @@ static int vega10_smu_init(struct pp_hwmgr *hwmgr)
 			&handle,
 			&mc_addr,
 			&kaddr);
-
 	if (ret)
-		return -EINVAL;
+		goto free_backend;
 
 	priv->smu_tables.entry[PPTABLE].version = 0x01;
 	priv->smu_tables.entry[PPTABLE].size = sizeof(PPTable_t);
@@ -511,6 +510,9 @@ err0:
 	amdgpu_bo_free_kernel(&priv->smu_tables.entry[PPTABLE].handle,
 			&priv->smu_tables.entry[PPTABLE].mc_addr,
 			&priv->smu_tables.entry[PPTABLE].table);
+free_backend:
+	kfree(hwmgr->smu_backend);
+
 	return -EINVAL;
 }