staging: vt6655: return early if not bNeedAck

This patch will check for bNeedAck before making bb_get_frame_time call, so
in case we dont need uAckTime, we can return early.

Signed-off-by: Matej Dujava <mdujava@kocurkovo.cz>
Link: https://lore.kernel.org/r/1588520570-14388-2-git-send-email-mdujava@kocurkovo.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/vt6655/rxtx.c

@@ -166,15 +166,16 @@ s_uGetTxRsvTime(
 	unsigned int uDataTime, uAckTime;
 
 	uDataTime = bb_get_frame_time(pDevice->byPreambleType, byPktType, cbFrameLength, wRate);
+
+	if (!bNeedAck)
+		return uDataTime;
+
 	if (byPktType == PK_TYPE_11B) /* llb,CCK mode */
 		uAckTime = bb_get_frame_time(pDevice->byPreambleType, byPktType, 14, (unsigned short)pDevice->byTopCCKBasicRate);
 	else /* 11g 2.4G OFDM mode & 11a 5G OFDM mode */
 		uAckTime = bb_get_frame_time(pDevice->byPreambleType, byPktType, 14, (unsigned short)pDevice->byTopOFDMBasicRate);
 
-	if (bNeedAck)
-		return uDataTime + pDevice->uSIFS + uAckTime;
-	else
-		return uDataTime;
+	return uDataTime + pDevice->uSIFS + uAckTime;
 }
 
 static __le16 vnt_rxtx_rsvtime_le16(struct vnt_private *priv, u8 pkt_type,