mac80211: freeing the wrong variable

The intent was to free "msp->ratelist" here.  "msp->sample_table" is
always NULL at this point.
Signed-off-by: Dan Carpenter <error27@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

net/mac80211/rc80211_minstrel_ht.c

@@ -748,7 +748,7 @@ minstrel_ht_alloc_sta(void *priv, struct ieee80211_sta *sta, gfp_t gfp)
 	return msp;
 
 error1:
-	kfree(msp->sample_table);
+	kfree(msp->ratelist);
 error:
 	kfree(msp);
 	return NULL;