staging: brcm80211: remove brcmf_find_msb() function

This function is similar to ffs() wihch is provided by the linux
kernel already. This patch replaces brcmf_find_msb() with ffs().

Reported-by: Johannes Berg <johannes@sipsolutions.net>
Reviewed-by: Franky (Zhenhui) Lin <frankyl@broadcom.com>
Reviewed-by: Roland Vossen <rvossen@broadcom.com>
Signed-off-by: Roland Vossen <rvossen@broadcom.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/staging/brcm80211/brcmfmac/wl_cfg80211.c

@@ -20,6 +20,7 @@
 #include <linux/kthread.h>
 #include <linux/netdevice.h>
 #include <linux/sched.h>
+#include <linux/bitops.h>
 #include <linux/etherdevice.h>
 #include <linux/ieee80211.h>
 #include <linux/mmc/sdio_func.h>
@@ -293,11 +294,6 @@ static s32 brcmf_iscan_pending(struct brcmf_cfg80211_priv *cfg_priv);
 static s32 brcmf_iscan_inprogress(struct brcmf_cfg80211_priv *cfg_priv);
 static s32 brcmf_iscan_aborted(struct brcmf_cfg80211_priv *cfg_priv);
 
-/*
-* find most significant bit set
-*/
-static __used u32 brcmf_find_msb(u16 bit16);
-
 /*
 * update pmklist to dongle
 */
@@ -2008,33 +2004,6 @@ brcmf_cfg80211_set_power_mgmt(struct wiphy *wiphy, struct net_device *dev,
 	return err;
 }
 
-static __used u32 brcmf_find_msb(u16 bit16)
-{
-	u32 ret = 0;
-
-	if (bit16 & 0xff00) {
-		ret += 8;
-		bit16 >>= 8;
-	}
-
-	if (bit16 & 0xf0) {
-		ret += 4;
-		bit16 >>= 4;
-	}
-
-	if (bit16 & 0xc) {
-		ret += 2;
-		bit16 >>= 2;
-	}
-
-	if (bit16 & 2)
-		ret += bit16 & 2;
-	else if (bit16)
-		ret += bit16;
-
-	return ret;
-}
-
 static s32
 brcmf_cfg80211_set_bitrate_mask(struct wiphy *wiphy, struct net_device *dev,
 			     const u8 *addr,
@@ -2062,10 +2031,10 @@ brcmf_cfg80211_set_bitrate_mask(struct wiphy *wiphy, struct net_device *dev,
 
 	rateset.count = le32_to_cpu(rateset.count);
 
-	legacy = brcmf_find_msb(mask->control[IEEE80211_BAND_2GHZ].legacy);
+	legacy = ffs(mask->control[IEEE80211_BAND_2GHZ].legacy & 0xFFFF);
 	if (!legacy)
-		legacy = brcmf_find_msb(
-				mask->control[IEEE80211_BAND_5GHZ].legacy);
+		legacy = ffs(mask->control[IEEE80211_BAND_5GHZ].legacy &
+			     0xFFFF);
 
 	val = wl_g_rates[legacy - 1].bitrate * 100000;