tests: fix ipmi-kcs-test leak

Spotted by ASAN.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
diff --git a/tests/ipmi-kcs-test.c b/tests/ipmi-kcs-test.c
index 9cf0b34..178ffc1 100644
--- a/tests/ipmi-kcs-test.c
+++ b/tests/ipmi-kcs-test.c
@@ -279,6 +279,7 @@
     cmdline = g_strdup_printf("-device ipmi-bmc-sim,id=bmc0"
                               " -device isa-ipmi-kcs,bmc=bmc0");
     qtest_start(cmdline);
+    g_free(cmdline);
     qtest_irq_intercept_in(global_qtest, "ioapic");
     qtest_add_func("/ipmi/local/kcs_base", test_kcs_base);
     qtest_add_func("/ipmi/local/kcs_abort", test_kcs_abort);