service/pam: fix free of wrong pointer in pam subprocess messaging

changelog/next.md

@@ -0,0 +1,3 @@
+## Bug Fixes
+
+- Fixed main process crashes on pam subprocess misbehavior.

src/services/pam/subprocess.cpp

@@ -201,6 +201,6 @@ int PamSubprocess::conversation(
 	return PAM_SUCCESS;
 
 fail:
-	free(responseArray); // NOLINT
+	free(responses); // NOLINT
 	_exit(1);
 }