Fixes the following W=1 kernel build warning(s):

 from drivers/net/wireless/broadcom/brcm80211/brcmsmac/main.c:27:
 drivers/net/wireless/broadcom/brcm80211/brcmsmac/main.c: In function ‘brcms_c_dotxstatus’:
 drivers/net/wireless/broadcom/brcm80211/brcmsmac/main.c:845:6: warning: variable ‘mcl’ set but not used [-Wunused-but-set-variable]
 drivers/net/wireless/broadcom/brcm80211/brcmsmac/main.c: In function ‘brcms_b_phy_reset’:
 drivers/net/wireless/broadcom/brcm80211/brcmsmac/main.c:1779:7: warning: variable ‘phy_in_reset’ set but not used [-Wunused-but-set-variable]
 drivers/net/wireless/broadcom/brcm80211/brcmsmac/main.c: In function ‘brcms_ucode_download’:
 drivers/net/wireless/broadcom/brcm80211/brcmsmac/main.c:2273:23: warning: variable ‘wlc’ set but not used [-Wunused-but-set-variable]
 drivers/net/wireless/broadcom/brcm80211/brcmsmac/main.c: In function ‘brcms_b_coreinit’:
 drivers/net/wireless/broadcom/brcm80211/brcmsmac/main.c:3176:6: warning: variable ‘sflags’ set but not used [-Wunused-but-set-variable]
 drivers/net/wireless/broadcom/brcm80211/brcmsmac/main.c: In function ‘brcms_c_set_chanspec’:
 drivers/net/wireless/broadcom/brcm80211/brcmsmac/main.c:3902:7: warning: variable ‘switchband’ set but not used [-Wunused-but-set-variable]
 drivers/net/wireless/broadcom/brcm80211/brcmsmac/main.c: In function ‘brcms_c_down’:
 drivers/net/wireless/broadcom/brcm80211/brcmsmac/main.c:5182:7: warning: variable ‘dev_gone’ set but not used [-Wunused-but-set-variable]
 drivers/net/wireless/broadcom/brcm80211/brcmsmac/main.c: In function ‘brcms_c_ofdm_rateset_war’:
 drivers/net/wireless/broadcom/brcm80211/brcmsmac/main.c:5393:5: warning: variable ‘r’ set but not used [-Wunused-but-set-variable]
 drivers/net/wireless/broadcom/brcm80211/brcmsmac/main.c: In function ‘mac80211_wlc_set_nrate’:
 drivers/net/wireless/broadcom/brcm80211/brcmsmac/main.c:5876:6: warning: variable ‘bcmerror’ set but not used [-Wunused-but-set-variable]
 drivers/net/wireless/broadcom/brcm80211/brcmsmac/main.c: In function ‘brcms_c_d11hdrs_mac80211’:
 drivers/net/wireless/broadcom/brcm80211/brcmsmac/main.c:6213:7: warning: variable ‘short_preamble’ set but not used [-Wunused-but-set-variable]

Cc: Arend van Spriel <arend.vanspriel@broadcom.com>
Cc: Franky Lin <franky.lin@broadcom.com>
Cc: Hante Meuleman <hante.meuleman@broadcom.com>
Cc: Chi-Hsien Lin <chi-hsien.lin@cypress.com>
Cc: Wright Feng <wright.feng@cypress.com>
Cc: Kalle Valo <kvalo@codeaurora.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Hauke Mehrtens <hauke@hauke-m.de>
Cc: linux-wireless@vger.kernel.org
Cc: brcm80211-dev-list.pdl@broadcom.com
Cc: brcm80211-dev-list@cypress.com
Cc: netdev@vger.kernel.org
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/20200821071644.109970-10-lee.jones@linaro.org