reiserfs: use per-fs commit workqueues

The reiserfs write lock hasn't been the BKL for some time. There's no
need to have different file systems queued up on the same workqueue.

Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: Jan Kara <jack@suse.cz>
diff --git a/fs/reiserfs/reiserfs.h b/fs/reiserfs/reiserfs.h
index 83d4eac..3f56746 100644
--- a/fs/reiserfs/reiserfs.h
+++ b/fs/reiserfs/reiserfs.h
@@ -431,6 +431,8 @@
 	/* Depth of the lock, start from -1 like the bkl */
 	int lock_depth;
 
+	struct workqueue_struct *commit_wq;
+
 	/* Comment? -Hans */
 	void (*end_io_handler) (struct buffer_head *, int);
 	hashf_t s_hash_function;	/* pointer to function which is used