b43: LP-PHY: Fix reading old mode in the set TX power control routine

Check the mode the hardware is in, not the mode we used the last time.
Signed-off-by: Gábor Stefanik <netrolller.3d@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

drivers/net/wireless/b43/phy_lp.c

@@ -1085,9 +1085,9 @@ static void lpphy_set_tx_power_control(struct b43_wldev *dev,
 	struct b43_phy_lp *lpphy = dev->phy.lp;
 	enum b43_lpphy_txpctl_mode oldmode;
 
-	oldmode = lpphy->txpctl_mode;
 	lpphy_read_tx_pctl_mode_from_hardware(dev);
-	if (lpphy->txpctl_mode == mode)
+	oldmode = lpphy->txpctl_mode;
+	if (oldmode == mode)
 		return;
 	lpphy->txpctl_mode = mode;