[XFS] make btree tracing generic

Make the existing bmap btree tracing generic so that it applies to all
btree types.

Some fragments lifted from a patch by Dave Chinner.

SGI-PV: 985583

SGI-Modid: xfs-linux-melb:xfs-kern:32187a

Signed-off-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
Signed-off-by: Bill O'Donnell <billodo@sgi.com>
Signed-off-by: David Chinner <david@fromorbit.com>
diff --git a/fs/xfs/xfs_inode.h b/fs/xfs/xfs_inode.h
index 3af1f6d..2a69a7d 100644
--- a/fs/xfs/xfs_inode.h
+++ b/fs/xfs/xfs_inode.h
@@ -245,7 +245,7 @@
 #ifdef XFS_BMAP_TRACE
 	struct ktrace		*i_xtrace;	/* inode extent list trace */
 #endif
-#ifdef XFS_BMBT_TRACE
+#ifdef XFS_BTREE_TRACE
 	struct ktrace		*i_btrace;	/* inode bmap btree trace */
 #endif
 #ifdef XFS_RW_TRACE