daemon: fix build without systemd-journal

Fix typo in OPTGROUP_JOURNAL_NOT_AVAILABLE
Define empty journal_finalize, called by mount.c

Signed-off-by: Olaf Hering <olaf@aepfle.de>
daemon: hivex: Define empty hivex_finalize function in case !HAVE_HIVEX.

Thanks: Olaf Hering (see previous commit).
lib: avoid pragma usage in journal.c

journal.c: In function 'guestfs__journal_get':
journal.c:120:9: error: #pragma GCC diagnostic not allowed inside functions
journal.c:121:9: error: #pragma GCC diagnostic not allowed inside functions
journal.c:123:9: error: #pragma GCC diagnostic not allowed inside functions
make[3]: *** [libguestfs_la-journal.lo] Error 1

Signed-off-by: Olaf Hering <olaf@aepfle.de>