afs: squash empty declaration warning

afs: squash empty declaration warning

Remove spurious semi-colon which generates a warning when
building under Solaris Studio.

  "./src/afs/UKERNEL/sysincludes.h", line ...: warning: syntax error:  empty declaration

Reviewed-on: https://gerrit.openafs.org/12957
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Benjamin Kaduk <kaduk@mit.edu>
(cherry picked from commit 306f0f3100e453e165032ae3bc9022b4a9a9a4c5)

Change-Id: Ie6657ab06c8d44b1452d9583908efd1596311971
Reviewed-on: https://gerrit.openafs.org/13106
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Michael Meffie <mmeffie@sinenomine.net>
Reviewed-by: Benjamin Kaduk <kaduk@mit.edu>