net: qlcnic: remove unused variable 'val' in qlcnic_83xx_cam_unlock()

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

drivers/net/ethernet/qlogic/qlcnic/qlcnic_83xx_hw.c:661:6: warning:
 variable 'val' set but not used [-Wunused-but-set-variable]
  661 |  u32 val;
      |      ^~~

After commit 7f966452 ("qlcnic: 83xx memory map and HW access
routines"), variable 'val' is never used in qlcnic_83xx_cam_unlock(), so
removing it to avoid build warning.
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Zhang Changzhong <zhangchangzhong@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

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

@@ -658,11 +658,10 @@ int qlcnic_83xx_cam_lock(struct qlcnic_adapter *adapter)
 void qlcnic_83xx_cam_unlock(struct qlcnic_adapter *adapter)
 {
 	void __iomem *addr;
-	u32 val;
 	struct qlcnic_hardware_context *ahw = adapter->ahw;
 
 	addr = ahw->pci_base0 + QLC_83XX_SEM_UNLOCK_FUNC(ahw->pci_func);
-	val = readl(addr);
+	readl(addr);
 }
 
 void qlcnic_83xx_read_crb(struct qlcnic_adapter *adapter, char *buf,