s4:torture:libnet: fix 'Conditional jump or move' valgrind error

s4:torture:libnet: fix 'Conditional jump or move' valgrind error

smbtorture test net.domopen.domopen generated the following valgrind
trace.

==29054== Conditional jump or move depends on uninitialised value(s)
==29054==    at 0x9788D31: libnet_DomainOpen_send (libnet_domain.c:617)
==29054==    by 0x9788E01: libnet_DomainOpen (libnet_domain.c:676)
==29054==    by 0x595F5D: test_domainopen (domain.c:41)
==29054==    by 0x5961AD: torture_domainopen (domain.c:101)
==29054==    by 0x9553F62: wrap_simple_test (torture.c:632)
==29054==    by 0x955368F: internal_torture_run_test (torture.c:442)
==29054==    by 0x9553A6B: torture_run_test_restricted (torture.c:542)
==29054==    by 0x26013F: run_matching (smbtorture.c:110)
==29054==    by 0x260001: run_matching (smbtorture.c:95)
==29054==    by 0x260260: torture_run_named_tests (smbtorture.c:143)
==29054==    by 0x261EDF: main (smbtorture.c:665)
==29054==
==29054== Conditional jump or move depends on uninitialised value(s)
==29054==    at 0x9788D95: libnet_DomainOpen_recv (libnet_domain.c:648)
==29054==    by 0x9788E1D: libnet_DomainOpen (libnet_domain.c:677)
==29054==    by 0x595F5D: test_domainopen (domain.c:41)
==29054==    by 0x5961AD: torture_domainopen (domain.c:101)
==29054==    by 0x9553F62: wrap_simple_test (torture.c:632)
==29054==    by 0x955368F: internal_torture_run_test (torture.c:442)
==29054==    by 0x9553A6B: torture_run_test_restricted (torture.c:542)
==29054==    by 0x26013F: run_matching (smbtorture.c:110)
==29054==    by 0x260001: run_matching (smbtorture.c:95)
==29054==    by 0x260260: torture_run_named_tests (smbtorture.c:143)

Signed-off-by: Noel Power <noel.power@suse.com>
Reviewed-by: Volker Lendecke <vl@samba.org>
Reviewed-by: Andreas Schneider <asn@samba.org>