mac80211: use le16_encode_bits() instead of open-coding

Instead of open-coding the equivalent of le16_encode_bits(),
just use that.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

net/mac80211/rx.c

@@ -549,7 +549,7 @@ ieee80211_add_rx_radiotap_header(struct ieee80211_local *local,
 
 	if (status->encoding == RX_ENC_HE &&
 	    status->flag & RX_FLAG_RADIOTAP_HE) {
-#define HE_PREP(f, val)	cpu_to_le16(FIELD_PREP(IEEE80211_RADIOTAP_HE_##f, val))
+#define HE_PREP(f, val)	le16_encode_bits(val, IEEE80211_RADIOTAP_HE_##f)
 
 		if (status->enc_flags & RX_ENC_FLAG_STBC_MASK) {
 			he.data6 |= HE_PREP(DATA6_NSTS,