Fix leak of securityDriverNames

When shutting down, the QEMU driver forgot to free the
securityDriverNames string list
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

src/qemu/qemu_driver.c

@@ -1134,6 +1134,9 @@ qemuShutdown(void) {
     VIR_FREE(qemu_driver->saveImageFormat);
     VIR_FREE(qemu_driver->dumpImageFormat);
 
+    for (i = 0 ; qemu_driver->securityDriverNames[i] != NULL ; i++)
+        VIR_FREE(qemu_driver->securityDriverNames[i]);
+    VIR_FREE(qemu_driver->securityDriverNames);
     virSecurityManagerFree(qemu_driver->securityManager);
 
     ebtablesContextFree(qemu_driver->ebtables);