xfs: buffer type overruns blf_flags field

The buffer type passed to log recvoery in the buffer log item
overruns the blf_flags field. I had assumed that flags field was a
32 bit value, and it turns out it is a unisgned short. Therefore
having 19 flags doesn't really work.

Convert the buffer type field to numeric value, and use the top 5
bits of the flags field for it. We currently have 17 types of
buffers, so using 5 bits gives us plenty of room for expansion in
future....

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Ben Myers <bpm@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>

diff --git a/fs/xfs/xfs_ialloc.c b/fs/xfs/xfs_ialloc.c
index 3039f82..c8f5ae1 100644
--- a/fs/xfs/xfs_ialloc.c
+++ b/fs/xfs/xfs_ialloc.c
@@ -1487,7 +1487,7 @@
 	/*
 	 * Log the allocation group inode header buffer.
 	 */
-	xfs_trans_buf_set_type(tp, bp, XFS_BLF_AGI_BUF);
+	xfs_trans_buf_set_type(tp, bp, XFS_BLFT_AGI_BUF);
 	xfs_trans_log_buf(tp, bp, first, last);
 }