drm: make drm_mm_init() return void

There is no reason to return "int" as this function never fails.
Furthermore, several drivers (ast, sis) already depend on this.

Signed-off-by: David Herrmann <dh.herrmann@gmail.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Dave Airlie <airlied@redhat.com>
diff --git a/drivers/gpu/drm/drm_gem.c b/drivers/gpu/drm/drm_gem.c
index bcedaf7..603f256 100644
--- a/drivers/gpu/drm/drm_gem.c
+++ b/drivers/gpu/drm/drm_gem.c
@@ -108,12 +108,8 @@
 		return -ENOMEM;
 	}
 
-	if (drm_mm_init(&mm->offset_manager, DRM_FILE_PAGE_OFFSET_START,
-			DRM_FILE_PAGE_OFFSET_SIZE)) {
-		drm_ht_remove(&mm->offset_hash);
-		kfree(mm);
-		return -ENOMEM;
-	}
+	drm_mm_init(&mm->offset_manager, DRM_FILE_PAGE_OFFSET_START,
+		    DRM_FILE_PAGE_OFFSET_SIZE);
 
 	return 0;
 }