drm/amdgpu: avoid drm error log during S3 on RHEL7.3

Signed-off-by: JimQu <Jim.Qu@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

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

@@ -519,6 +519,7 @@ static int amdgpu_cs_parser_bos(struct amdgpu_cs_parser *p,
 		r = ttm_eu_reserve_buffers(&p->ticket, &p->validated, true,
 					   &duplicates);
 		if (unlikely(r != 0)) {
+			if (r != -ERESTARTSYS)
 				DRM_ERROR("ttm_eu_reserve_buffers failed.\n");
 			goto error_free_pages;
 		}