test: fix

- Address sanitizer may call sigaltstack().
  Add it to the syscall whitelist (debug only).
- Fix args count checking for `check-bookmarkfs-util watcher`.

src/sandbox.c

@@ -178,6 +178,10 @@ sandbox_enter (
 
         // signals
         SCMP_RULE_NOARG(sigaction,       10),
+#ifdef BOOKMARKFS_DEBUG
+        // Make ASAN happy...
+        SCMP_RULE_NOARG(sigaltstack,     0),
+#endif
         SCMP_RULE_NOARG(sigprocmask,     10),
         SCMP_RULE_NOARG(sigreturn,       10),
         SCMP_RULE_NOARG(restart_syscall, 10),

tests/check_watcher.c

@@ -169,6 +169,7 @@ check_watcher (
       default:
         return -1;
     }
+    argc -= optind;
     if (argc < 1) {
         return -1;
     }