storage: Don't check the output of virGetUserConfigDirectory()

virGetUserConfigDirectory() *never* *ever* returns NULL, making the
checks for it completely unnecessary.
Signed-off-by: NFabiano Fidêncio <fidencio@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>

src/storage/storage_driver.c

@@ -278,7 +278,7 @@ storageStateInitialize(bool privileged,
     } else {
         configdir = virGetUserConfigDirectory();
         rundir = virGetUserRuntimeDirectory();
-        if (!(configdir && rundir))
+        if (!rundir)
             goto error;
 
         driver->configDir = g_strdup_printf("%s/storage", configdir);