tests: Avoid needless call to pthread_exit()

Signed-off-by: Jakub Jelen <jjelen@redhat.com>
Reviewed-by: Andreas Schneider <asn@cryptomilk.org>
(cherry picked from commit 444982b38a)

tests/client/torture_gssapi_auth.c

@@ -272,5 +272,5 @@ torture_run_tests(void)
     rc = cmocka_run_group_tests(tests, sshd_setup, sshd_teardown);
     ssh_finalize();
 
-    pthread_exit((void *)&rc);
+    return rc;
 }