net: qlcnic: add missed unlock in qlcnic_83xx_flash_read32

[ Upstream commit 0a298d1 ]

qlcnic_83xx_unlock_flash() is called on all paths after we call
qlcnic_83xx_lock_flash(), except for one error path on failure
of QLCRD32(), which may cause a deadlock. This bug is suggested
by a static analysis tool, please advise.

Fixes: 81d0aeb ("qlcnic: flash template based firmware reset recovery")
Signed-off-by: Dinghao Liu <dinghao.liu@zju.edu.cn>
Link: https://lore.kernel.org/r/20210816131405.24024-1-dinghao.liu@zju.edu.cn
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

drivers/net/ethernet/qlogic/qlcnic/qlcnic_83xx_hw.c

@@ -3156,8 +3156,10 @@ int qlcnic_83xx_flash_read32(struct qlcnic_adapter *adapter, u32 flash_addr,
 
 		indirect_addr = QLC_83XX_FLASH_DIRECT_DATA(addr);
 		ret = QLCRD32(adapter, indirect_addr, &err);
-		if (err == -EIO)
+		if (err == -EIO) {
+			qlcnic_83xx_unlock_flash(adapter);
 			return err;
+		}
 
 		word = ret;
 		*(u32 *)p_data  = word;