wifi: brcmsmac: remove unused has_5g variable

clang with W=1 reports
drivers/net/wireless/broadcom/brcm80211/brcmsmac/mac80211_if.c:1051:6: error:
  variable 'has_5g' set but not used [-Werror,-Wunused-but-set-variable]
        int has_5g = 0;
            ^
This variable is not used so remove it.
Signed-off-by: Tom Rix <trix@redhat.com>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Signed-off-by: Kalle Valo <kvalo@kernel.org>
Link: https://lore.kernel.org/r/20230325130343.1334209-1-trix@redhat.com

drivers/net/wireless/broadcom/brcm80211/brcmsmac/mac80211_if.c

@@ -1048,7 +1048,6 @@ static int ieee_hw_rate_init(struct ieee80211_hw *hw)
 	struct brcms_info *wl = hw->priv;
 	struct brcms_c_info *wlc = wl->wlc;
 	struct ieee80211_supported_band *band;
-	int has_5g = 0;
 	u16 phy_type;
 
 	hw->wiphy->bands[NL80211_BAND_2GHZ] = NULL;
@@ -1070,7 +1069,6 @@ static int ieee_hw_rate_init(struct ieee80211_hw *hw)
 
 	/* Assume all bands use the same phy.  True for 11n devices. */
 	if (wl->pub->_nbands > 1) {
-		has_5g++;
 		if (phy_type == PHY_TYPE_N || phy_type == PHY_TYPE_LCN) {
 			band = &wlc->bandstate[BAND_5G_INDEX]->band;
 			*band = brcms_band_5GHz_nphy_template;