quota: Use mark_inode_dirty_sync instead of mark_inode_dirty

Quota code never touches file data. It just modifies i_blocks + i_bytes
of inodes and inode flags of quota files. So use mark_inode_dirty_sync
instead of mark_inode_dirty.

Signed-off-by: Jan Kara <jack@suse.cz>
diff --git a/fs/quota/dquot.c b/fs/quota/dquot.c
index b171221..a7023bc 100644
--- a/fs/quota/dquot.c
+++ b/fs/quota/dquot.c
@@ -1992,7 +1992,7 @@
 				truncate_inode_pages(&toputinode[cnt]->i_data,
 						     0);
 				mutex_unlock(&toputinode[cnt]->i_mutex);
-				mark_inode_dirty(toputinode[cnt]);
+				mark_inode_dirty_sync(toputinode[cnt]);
 			}
 			mutex_unlock(&dqopt->dqonoff_mutex);
 		}