s3: Fix a valgrind error

s3: Fix a valgrind error

For me this fixes

==1950== Invalid read of size 4
==1950==    at 0x81EBED5: GUID_equal (uuid.c:239)
==1950==    by 0x81E51AB: ndr_syntax_id_equal (ndr_misc.c:35)
==1950==    by 0x82EB0D1: get_iface_from_syntax (rpc_common.c:160)
==1950==    by 0x82EB25E: get_pipe_name_from_syntax (rpc_common.c:179)
==1950==    by 0x8509E4F: close_policy_by_pipe (rpc_handles.c:322)
==1950==    by 0x8507941: close_internal_rpc_pipe_hnd (rpc_ncacn_np.c:109)
==1950==    by 0x468270: _talloc_free_internal (talloc.c:826)
==1950==    by 0x467EE0: _talloc_free_internal (talloc.c:1268)
==1950==    by 0x467EE0: _talloc_free_internal (talloc.c:1268)
==1950==    by 0x467EE0: _talloc_free_internal (talloc.c:1268)
==1950==    by 0x467EE0: _talloc_free_internal (talloc.c:1268)
==1950==    by 0x80E6487: sam_trusted_domains (winbindd_samr.c:406)
==1950==  Address 0x687ea4 is 20 bytes inside a block of size 40 free'd
==1950==    at 0x58CDC: free (in /usr/local/lib/valgrind/vgpreload_memcheck-x86-freebsd.so)
==1950==    by 0x8507812: free_pipe_rpc_context_internal (rpc_ncacn_np.c:74)
==1950==    by 0x8507936: close_internal_rpc_pipe_hnd (rpc_ncacn_np.c:106)
==1950==    by 0x468270: _talloc_free_internal (talloc.c:826)
==1950==    by 0x467EE0: _talloc_free_internal (talloc.c:1268)
==1950==    by 0x467EE0: _talloc_free_internal (talloc.c:1268)
==1950==    by 0x467EE0: _talloc_free_internal (talloc.c:1268)
==1950==    by 0x467EE0: _talloc_free_internal (talloc.c:1268)
==1950==    by 0x80E6487: sam_trusted_domains (winbindd_samr.c:406)
==1950==    by 0x80C2F85: trusted_domains (winbindd_cache.c:2820)
==1950==    by 0x80D5188: winbindd_dual_list_trusted_domains (winbindd_misc.c:162)
==1950==    by 0x80E987F: wb_child_request_trigger (winbindd_dual.c:437)
==1950==

Andreas, Guenther, please check!

Autobuild-User: Volker Lendecke <vlendec@samba.org>
Autobuild-Date: Sun Jun  5 13:19:39 CEST 2011 on sn-devel-104