tests: fix ipmi-kcs-test leak

Spotted by ASAN.
Signed-off-by: NMarc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: NPhilippe Mathieu-Daudé <f4bug@amsat.org>

tests/ipmi-kcs-test.c

@@ -279,6 +279,7 @@ int main(int argc, char **argv)
     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);