s4:libcli: fix 'Conditional jump or move' valgrind error

s4:libcli: fix 'Conditional jump or move' valgrind error

smbtorture test base.tcondev.tcondev causes the following valgrind trace

==23282== Conditional jump or move depends on uninitialised value(s)
==23282==    at 0x9BE5632: smbcli_tconX (cliconnect.c:148)
==23282==    by 0x41021C: tcon_devtest (base.c:91)
==23282==    by 0x411A01: run_tcon_devtype_test (base.c:522)
==23282==    by 0x16B21D: wrap_simple_1smb_test (util_smb.c:856)
==23282==    by 0x955368F: internal_torture_run_test (torture.c:442)
==23282==    by 0x9553A6B: torture_run_test_restricted (torture.c:542)
==23282==    by 0x2600A4: run_matching (smbtorture.c:110)
==23282==    by 0x25FF66: run_matching (smbtorture.c:95)
==23282==    by 0x2601C5: torture_run_named_tests (smbtorture.c:143)
==23282==    by 0x261E44: main (smbtorture.c:665)
==23282==

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