xfs: remove unused XBT_FORCE_SLEEP bit

XBT_FORCE_SLEEP is no longer ever tested; it is only set
and cleared.  Remove it.
Signed-off-by: Eric Sandeen <sandeen@sandeen.net>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Ben Myers <bpm@sgi.com>

fs/xfs/xfs_buf.c

@@ -1701,12 +1701,8 @@ xfsbufd(
 		struct list_head tmp;
 		struct blk_plug plug;
 
-		if (unlikely(freezing(current))) {
-			set_bit(XBT_FORCE_SLEEP, &target->bt_flags);
+		if (unlikely(freezing(current)))
 			refrigerator();
-		} else {
-			clear_bit(XBT_FORCE_SLEEP, &target->bt_flags);
-		}
 
 		/* sleep for a long time if there is nothing to do. */
 		if (list_empty(&target->bt_delwri_queue))

fs/xfs/xfs_buf.h

@@ -90,8 +90,7 @@ typedef unsigned int xfs_buf_flags_t;
 	{ _XBF_DELWRI_Q,	"DELWRI_Q" }
 
 typedef enum {
-	XBT_FORCE_SLEEP = 0,
-	XBT_FORCE_FLUSH = 1,
+	XBT_FORCE_FLUSH = 0,
 } xfs_buftarg_flags_t;
 
 typedef struct xfs_buftarg {