tests: fix vhost-user-test leak

Spotted by valgrind.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
diff --git a/tests/vhost-user-test.c b/tests/vhost-user-test.c
index 46d0588..27b10c1 100644
--- a/tests/vhost-user-test.c
+++ b/tests/vhost-user-test.c
@@ -683,6 +683,7 @@
                                   qtest_get_arch());
     g_test_trap_subprocess(path, 0, 0);
     g_test_trap_assert_passed();
+    g_free(path);
 }
 #endif