drm/amdgpu: Free user pages if kvmalloc_array fails

To cleanup the BOs of bo_list which have got user pages.
Signed-off-by: Philip Yang <Philip.Yang@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Felix Kuehling <Felix.Kuehling@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

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

@@ -543,7 +543,8 @@ static int amdgpu_cs_parser_bos(struct amdgpu_cs_parser *p,
 					GFP_KERNEL | __GFP_ZERO);
 		if (!e->user_pages) {
 			DRM_ERROR("kvmalloc_array failure\n");
-			return -ENOMEM;
+			r = -ENOMEM;
+			goto out_free_user_pages;
 		}
 
 		r = amdgpu_ttm_tt_get_user_pages(bo, e->user_pages);