staging: rtl8192u: Fix typo in comment

Fix the typo "cheked" -> "checked" in comment
Signed-off-by: Xianting Tian <xianting_tian@126.com>
Link: https://lore.kernel.org/r/1573306614-21490-1-git-send-email-xianting_tian@126.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/rtl8192u/ieee80211/ieee80211_softmac.c

@@ -2331,7 +2331,7 @@ void ieee80211_start_bss(struct ieee80211_device *ieee)
 
 	/* ensure no-one start an associating process (thus setting
 	 * the ieee->state to ieee80211_ASSOCIATING) while we
-	 * have just cheked it and we are going to enable scan.
+	 * have just checked it and we are going to enable scan.
 	 * The ieee80211_new_net function is always called with
 	 * lock held (from both ieee80211_softmac_check_all_nets and
 	 * the rx path), so we cannot be in the middle of such function