mac80211: use non-atomic bitmap operation for local variable

For a local variable there's no need to use the atomic
set_bit() operation, use __set_bit() instead.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
diff --git a/net/mac80211/util.c b/net/mac80211/util.c
index 51a4a25..ea8a674 100644
--- a/net/mac80211/util.c
+++ b/net/mac80211/util.c
@@ -821,7 +821,7 @@
 		if (elem_parse_failed)
 			elems->parse_error = true;
 		else
-			set_bit(id, seen_elems);
+			__set_bit(id, seen_elems);
 
 		left -= elen;
 		pos += elen;