wireless, mwifiex: drop redundant NULL test before call to release_firmware()

Since release_firmware() does its own test for NULL it is redundant to
do so before calling it.

Signed-off-by: Jesper Juhl <jj@chaosbits.net>
Acked-by: Bing Zhao <bzhao@marvell.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/mwifiex/main.c b/drivers/net/wireless/mwifiex/main.c
index 9d1b3ca..2ee6162 100644
--- a/drivers/net/wireless/mwifiex/main.c
+++ b/drivers/net/wireless/mwifiex/main.c
@@ -342,8 +342,7 @@
 	ret = 0;
 
 done:
-	if (adapter->firmware)
-		release_firmware(adapter->firmware);
+	release_firmware(adapter->firmware);
 	if (ret)
 		ret = -1;
 	return ret;