firmware: add missing kfree for work on async call

The recent fix to use kstrdup_const() failed to add a
kfree upon failure of name allocation...

Cc: Ming Lei <ming.lei@canonical.com>
Cc: Seth Forshee <seth.forshee@canonical.com>
Cc: Kyle McMartin <kyle@kernel.org>
Signed-off-by: NLuis R. Rodriguez <mcgrof@suse.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/base/firmware_class.c

@@ -1307,8 +1307,10 @@ request_firmware_nowait(
 
 	fw_work->module = module;
 	fw_work->name = kstrdup_const(name, gfp);
-	if (!fw_work->name)
+	if (!fw_work->name) {
+		kfree(fw_work);
 		return -ENOMEM;
+	}
 	fw_work->device = device;
 	fw_work->context = context;
 	fw_work->cont = cont;