build: drop the getopt-posix gnulib module

The getopt-posix module fixes a problem with optind being incorrectly
set after a failed option parse. It was also previously used to allow
the bhyve driver to access a private internal reentrant getopt impl.
None of this matters to libvirt code any more.

This partially reverts

  commit b436a8ae
  Author: Fabian Freyer <fabian.freyer@physik.tu-berlin.de>
  Date:   Thu Jun 9 00:50:35 2016 +0000

    gnulib: add getopt module
Reviewed-by: NJán Tomko <jtomko@redhat.com>
Signed-off-by: NDaniel P. Berrangé <berrange@redhat.com>

bootstrap.conf

@@ -51,7 +51,6 @@ fsync
 getaddrinfo
 getcwd-lgpl
 gethostname
-getopt-posix
 getpass
 getpeername
 getsockname

m4/virt-driver-bhyve.m4

@@ -51,9 +51,6 @@ AC_DEFUN([LIBVIRT_DRIVER_CHECK_BHYVE],[
     AM_CONDITIONAL([WITH_BHYVE], [test "$with_bhyve" = "yes"])
 ])
 
-dnl Build with gnulib's getopt which contains a reentrant interface
-AC_DEFUN([gl_REPLACE_GETOPT_ALWAYS], [])
-
 AC_DEFUN([LIBVIRT_DRIVER_RESULT_BHYVE],[
     LIBVIRT_RESULT([Bhyve], [$with_bhyve])
 ])

po/POTFILES

 gnulib/lib/gai_strerror.c
-gnulib/lib/getopt.c
 gnulib/lib/regcomp.c
 src/access/viraccessdriverpolkit.c
 src/access/viraccessmanager.c