mwifiex: fix a comment typo

Just fix a typo in the code comment.
Signed-off-by: Geliang Tang <geliangtang@163.com>
Acked-by: Amitkumar Karwar <akarwar@marvell.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>

drivers/net/wireless/mwifiex/cfg80211.c

@@ -2374,7 +2374,7 @@ mwifiex_cfg80211_leave_ibss(struct wiphy *wiphy, struct net_device *dev)
  * CFG802.11 operation handler for scan request.
  *
  * This function issues a scan request to the firmware based upon
- * the user specified scan configuration. On successfull completion,
+ * the user specified scan configuration. On successful completion,
  * it also informs the results.
  */
 static int