xfs: remove XFS_BMAP_TRACE_EXLIST

xfs: remove XFS_BMAP_TRACE_EXLIST

Source kernel commit: e8e0e170e2e17b601b86edb86f58dbf7c599e4b3

Instead of looping over all extents in some debug-only helper just
insert trace points into the loops that already exist in the calling
functions.

Also split the xfs_extlist trace point into one each for reading and
writing extents from disk.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
[sandeen: userspace-specific tracepoint macro updates]
Signed-off-by: Eric Sandeen <sandeen@sandeen.net>