brcmfmac: add missing curly braces in brcmf_fws_txstatus_suppressed()

The 0-day testing from Fenguang Wu issued the following warning:

tree:   git://git.kernel.org/pub/scm/linux/kernel/git/linville/wireless-next.git

 master
head:   4b074b07
commit: 1e86d696
    [33/59] brcmfmac: Update fwsignal to fix out of order tx.

>> drivers/net/wireless/brcm80211/brcmfmac/fwsignal.c:1393:2-56:
    code aligned with following code on line 1394

vim +1393 drivers/net/wireless/brcm80211/brcmfmac/fwsignal.c

84bcc0c3  1387 	}
84bcc0c3  1388
84bcc0c3  1389 	entry->generation = genbit;
84bcc0c3  1390
2747e5f7  1391 	ret = brcmf_proto_hdrpull(fws->drvr, false, &ifidx, skb);
2747e5f7  1392 	if (ret == 0)
1e86d696 @1393 		brcmf_skb_htod_tag_set_field(skb, GENERATION, ..
1e86d696 @1394 		brcmf_skbcb(skb)->htod_seq = seq;
1e86d696  1395 		if (brcmf_skb_htod_seq_get_field(skb, FROMFW)) {
1e86d696  1396 			brcmf_skb_htod_seq_set_field(skb, ..
1e86d696  1397 			brcmf_skb_htod_seq_set_field(skb, ..

This warning is valid and the if statement needs curly braces here.

Reported-by: Fengguang Wu <fengguang.wu@intel.com>
Reviewed-by: Hante Meuleman <meuleman@broadcom.com>
Reviewed-by: Pieter-Paul Giesberts <pieterpg@broadcom.com>
Signed-off-by: Arend van Spriel <arend@broadcom.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>