s3:torture:LOCAL-IDMAP-TDB-COMMON: avoid talloc stacktrace

The short version is:

Running LOCAL-IDMAP-TDB-COMMON
test_getnewid1: PASSED!
test_setmap1: PASSED!
test_unixid2sid1: PASSED!
test_sid2unixid1: could not create uid map!
TEST LOCAL-IDMAP-TDB-COMMON FAILED!
LOCAL-IDMAP-TDB-COMMON took 0.029819 secs

Freed frame ../../source3/torture/torture.c:15748, expected ../../source3/torture/test_idmap_tdb_common.c:986.
===============================================================
INTERNAL ERROR: Frame not freed in order. in pid 3692106 (4.19.0pre1-DEVELOPERBUILD)
If you are running a recent Samba version, and if you think this problem is not yet fixed in the latest versions, please consider reporting this bug, see https://wiki.samba.org/index.php/Bug_Reporting
===============================================================
PANIC (pid 3692106): Frame not freed in order. in 4.19.0pre1-DEVELOPERBUILD
BACKTRACE: 11 stack frames:
 #0 bin/shared/private/libgenrand-samba4.so(log_stack_trace+0x32) [0x7f2f39b430ba]
 #1 bin/shared/private/libgenrand-samba4.so(smb_panic_log+0x1dd) [0x7f2f39b43037]
 #2 bin/shared/private/libgenrand-samba4.so(smb_panic+0x1c) [0x7f2f39b43056]
 #3 bin/shared/libsamba-util.so.0(+0x75309) [0x7f2f3a659309]
 #4 bin/shared/private/libtalloc-samba4.so(+0x5cc6) [0x7f2f3a758cc6]
 #5 bin/shared/private/libtalloc-samba4.so(+0x6173) [0x7f2f3a759173]
 #6 bin/shared/private/libtalloc-samba4.so(_talloc_free+0x10c) [0x7f2f3a75a54b]
 #7 /data/samba/samba-review/bin/smbtorture3(main+0xa97) [0x55cb3dc8cedc]
 #8 /lib/x86_64-linux-gnu/libc.so.6(+0x29d90) [0x7f2f396d4d90]
 #9 /lib/x86_64-linux-gnu/libc.so.6(__libc_start_main+0x80) [0x7f2f396d4e40]
 #10 /data/samba/samba-review/bin/smbtorture3(_start+0x25) [0x55cb3dc59895]
smb_panic(): calling panic action [/data/samba/samba-review/selftest/gdb_backtrace 3692106]

Signed-off-by: Douglas Bagnall <douglas.bagnall@catalyst.net.nz>
Reviewed-by: Andrew Bartlett <abartlet@samba.org>

source3/torture/test_idmap_tdb_common.c

@@ -977,7 +977,7 @@ static bool test_unixids2sids3(TALLOC_CTX *memctx, struct idmap_domain *dom)
 	return retval;
 }
 
-#define CHECKRESULT(r) if(!r) {return r;}
+#define CHECKRESULT(r) if(!r) {TALLOC_FREE(stack); return r;}
 
 bool run_idmap_tdb_common_test(int dummy)
 {
@@ -989,11 +989,13 @@ bool run_idmap_tdb_common_test(int dummy)
 
 	dom = createdomain(memctx);
 	if (dom == NULL) {
+		TALLOC_FREE(stack);
 		return false;
 	}
 
 	status = dom->methods->init(dom);
 	if (!NT_STATUS_IS_OK(status)) {
+		TALLOC_FREE(stack);
 		return false;
 	}