b43: Fix assigning negative value to unsigned variable

stable inclusion
from stable-v5.10.121
commit cc575b855809b9cf12b8e111b3c5f1bc02b9424a
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I5L6CQ

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=cc575b855809b9cf12b8e111b3c5f1bc02b9424a

--------------------------------

[ Upstream commit 11800d89 ]

fix warning reported by smatch:
drivers/net/wireless/broadcom/b43/phy_n.c:585 b43_nphy_adjust_lna_gain_table()
warn: assigning (-2) to unsigned variable '*(lna_gain[0])'
Signed-off-by: NHaowen Bai <baihaowen@meizu.com>
Signed-off-by: NKalle Valo <kvalo@kernel.org>
Link: https://lore.kernel.org/r/1648203315-28093-1-git-send-email-baihaowen@meizu.comSigned-off-by: NSasha Levin <sashal@kernel.org>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>
Acked-by: NXie XiuQi <xiexiuqi@huawei.com>

drivers/net/wireless/broadcom/b43/phy_n.c

@@ -582,7 +582,7 @@ static void b43_nphy_adjust_lna_gain_table(struct b43_wldev *dev)
 	u16 data[4];
 	s16 gain[2];
 	u16 minmax[2];
-	static const u16 lna_gain[4] = { -2, 10, 19, 25 };
+	static const s16 lna_gain[4] = { -2, 10, 19, 25 };
 
 	if (nphy->hang_avoid)
 		b43_nphy_stay_in_carrier_search(dev, 1);