r600g: fix wwarning in bo_map function
diff --git a/src/gallium/winsys/r600/drm/r600_priv.h b/src/gallium/winsys/r600/drm/r600_priv.h
index f39778d..fdca6f0 100644
--- a/src/gallium/winsys/r600/drm/r600_priv.h
+++ b/src/gallium/winsys/r600/drm/r600_priv.h
@@ -145,6 +145,7 @@
 static inline int radeon_bo_map(struct radeon *radeon, struct radeon_bo *bo)
 {
 	bo->map_count++;
+	return 0;
 }
 
 static inline void radeon_bo_unmap(struct radeon *radeon, struct radeon_bo *bo)