[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/Makefile b/fs/xfs/Makefile
index 737c9a4..75b2be7 100644
--- a/fs/xfs/Makefile
+++ b/fs/xfs/Makefile
@@ -91,7 +91,8 @@
 				   xfs_dmops.o \
 				   xfs_qmops.o
 
-xfs-$(CONFIG_XFS_TRACE)		+= xfs_dir2_trace.o
+xfs-$(CONFIG_XFS_TRACE)		+= xfs_btree_trace.o \
+				   xfs_dir2_trace.o
 
 # Objects in linux/
 xfs-y				+= $(addprefix $(XFS_LINUX)/, \