aklog: Do not include XCFLAGS twice

aklog: Do not include XCFLAGS twice

In aklog, we set MODULE_CFLAGS to XCFLAGS and some other things.
However, when using AFS_LDRULE or AFS_CCRULE, CFLAGS will contain
MT_CFLAGS, which contains XCFLAGS. The end result is that the contents
of XCFLAGS appear twice in the compilation invocation, breaking some
platforms like HP-UX where the order of XCFLAGS relative to other
things is a bit fragile.

Fix this by removing XCFLAGS from the MODULE_CFLAGS definition.

Change-Id: I5eef9764d758885a995269edc5bef91ff06db8b5
Reviewed-on: http://gerrit.openafs.org/3960
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Derrick Brashear <shadow@dementia.org>