All other instances of call to __argp_failure() where there is
a dgettext() call is first checking whether state is NULL before
attempting to dereference it to get the root_argp->argp_domain.
Fixes: CID 292436
Signed-off-by: Darren Kenny <darren.kenny@oracle.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>