xfs_repair: add XR_DIR_TRACE to dir2.c

xfs_repair: add XR_DIR_TRACE to dir2.c

attr_repair.c has many printf-tracepoints under
#ifdef XR_DIR_TRACE, but the similar code in dir2.c does not.

Add these same tracepoints to remove more differences between
these two pieces of code.

Not all messages are quite correct; those will be fixed up last.
For now we just make the code more obviously similar.

Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Eric Sandeen <sandeen@sandeen.net>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>