radiotap: Avoid ubsan warning on 1<<31

Use the BIT() macro and unsigned int to avoid ubsan warning on 1<<31 not
fitting in an int.

Signed-off-by: Jouni Malinen <j@w1.fi>

src/utils/radiotap.c

@@ -123,13 +123,13 @@ int ieee80211_radiotap_iterator_init(
 
 	/* find payload start allowing for extended bitmap(s) */
 
-	if (iterator->_bitmap_shifter & (1<<IEEE80211_RADIOTAP_EXT)) {
+	if (iterator->_bitmap_shifter & BIT(IEEE80211_RADIOTAP_EXT)) {
 		if ((unsigned long)iterator->_arg -
 		    (unsigned long)iterator->_rtheader + sizeof(uint32_t) >
 		    (unsigned long)iterator->_max_length)
 			return -EINVAL;
 		while (get_unaligned_le32(iterator->_arg) &
-					(1 << IEEE80211_RADIOTAP_EXT)) {
+		       BIT(IEEE80211_RADIOTAP_EXT)) {
 			iterator->_arg += sizeof(uint32_t);
 
 			/*