s4:torture:basic: fix 'Syscall param writev(vector[...])' valgrind error

s4:torture:basic: fix 'Syscall param writev(vector[...])' valgrind error

smbtorture test  base.winattr.winattr yields the following trace

==25514== Syscall param writev(vector[...]) points to uninitialised byte(s)
==25514==    at 0xFBA2C87: writev (in /lib64/libc-2.19.so)
==25514==    by 0x106CB033: writev_handler (async_sock.c:340)
==25514==    by 0xF67812A: ??? (in /usr/lib64/libtevent.so.0.9.26)
==25514==    by 0xF6765F6: ??? (in /usr/lib64/libtevent.so.0.9.26)
==25514==    by 0xF6727FC: _tevent_loop_once (in /usr/lib64/libtevent.so.0.9.26)
==25514==    by 0x5AE3400: smbcli_request_receive (rawrequest.c:416)
==25514==    by 0x5AEEC7E: smb_raw_nttrans_recv (rawtrans.c:408)
==25514==    by 0x5AF6543: smb_raw_query_secdesc_recv (rawacl.c:67)
==25514==    by 0x5AF580F: smb_raw_fileinfo_recv (rawfileinfo.c:699)
==25514==    by 0x5AF58BE: smb_raw_fileinfo (rawfileinfo.c:721)
==25514==    by 0x454AC3: torture_winattrtest (attr.c:217)
==25514==    by 0x16B21D: wrap_simple_1smb_test (util_smb.c:856)
==25514==    by 0x955368F: internal_torture_run_test (torture.c:442)
==25514==    by 0x9553A6B: torture_run_test_restricted (torture.c:542)
==25514==    by 0x2600A4: run_matching (smbtorture.c:110)
==25514==    by 0x25FF66: run_matching (smbtorture.c:95)
==25514==    by 0x2601C5: torture_run_named_tests (smbtorture.c:143)
==25514==    by 0x261E44: main (smbtorture.c:665)
==25514==  Address 0x187d69c6 is 598 bytes inside a block of size 1,325 alloc'd
==25514==    at 0x4C29110: malloc (in /usr/lib64/valgrind/vgpreload_memcheck-amd64-linux.so)
==25514==    by 0xF464A73: _talloc_pooled_object (in /usr/lib64/libtalloc.so.2.1.5)
==25514==    by 0xF67366D: _tevent_req_create (in /usr/lib64/libtevent.so.0.9.26)
==25514==    by 0xB0D49FF: smb1cli_req_create (smbXcli_base.c:1322)
==25514==    by 0xB0E1E6D: smb1cli_trans_send (smb1cli_trans.c:512)
==25514==    by 0x5AEE9B2: smb_raw_nttrans_send (rawtrans.c:310)
==25514==    by 0x5AF64F0: smb_raw_query_secdesc_send (rawacl.c:51)
==25514==    by 0x5AF56E5: smb_raw_fileinfo_send (rawfileinfo.c:658)
==25514==    by 0x5AF58A3: smb_raw_fileinfo (rawfileinfo.c:720)
==25514==    by 0x454AC3: torture_winattrtest (attr.c:217)
==25514==    by 0x16B21D: wrap_simple_1smb_test (util_smb.c:856)
==25514==    by 0x955368F: internal_torture_run_test (torture.c:442)
==25514==    by 0x9553A6B: torture_run_test_restricted (torture.c:542)
==25514==    by 0x2600A4: run_matching (smbtorture.c:110)
==25514==    by 0x25FF66: run_matching (smbtorture.c:95)
==25514==    by 0x2601C5: torture_run_named_tests (smbtorture.c:143)
==25514==    by 0x261E44: main (smbtorture.c:665)

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