gfs2: nit: gfs2_drop_inode shouldn't return bool

Today, gfs2_drop_inode can return "false" for an int value.
I'm sure this was just an oversight. Change to int value.
Signed-off-by: Bob Peterson <rpeterso@redhat.com>

fs/gfs2/super.c

@@ -947,7 +947,7 @@ static int gfs2_drop_inode(struct inode *inode)
 		gfs2_glock_hold(gl);
 		if (!gfs2_queue_delete_work(gl, 0))
 			gfs2_glock_queue_put(gl);
-		return false;
+		return 0;
 	}
 
 	return generic_drop_inode(inode);