net: ethernet: et131x: Remove unused variable 'pm_csr'

Gcc report warning as follows:

drivers/net/ethernet/agere/et131x.c:953:6: warning:
 variable 'pm_csr' set but not used [-Wunused-but-set-variable]
  953 |  u32 pm_csr;
      |      ^~~~~~
drivers/net/ethernet/agere/et131x.c:1002:6:warning:
 variable 'pm_csr' set but not used [-Wunused-but-set-variable]
 1002 |  u32 pm_csr;
      |      ^~~~~~
drivers/net/ethernet/agere/et131x.c:3446:8: warning:
 variable 'pm_csr' set but not used [-Wunused-but-set-variable]
 3446 |    u32 pm_csr;
      |        ^~~~~~

After commit 38df6492 ("et131x: Add PCIe gigabit ethernet driver
et131x to drivers/net"), 'pm_csr' is never used in these functions,
so removing it to avoid build warning.
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Zhang Changzhong <zhangchangzhong@huawei.com>
Acked-by: Mark Einon <mark.einon@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/agere/et131x.c

@@ -950,7 +950,6 @@ static void et1310_setup_device_for_multicast(struct et131x_adapter *adapter)
 	u32 hash2 = 0;
 	u32 hash3 = 0;
 	u32 hash4 = 0;
-	u32 pm_csr;
 
 	/* If ET131X_PACKET_TYPE_MULTICAST is specified, then we provision
 	 * the multi-cast LIST.  If it is NOT specified, (and "ALL" is not
@@ -984,7 +983,7 @@ static void et1310_setup_device_for_multicast(struct et131x_adapter *adapter)
 	}
 
 	/* Write out the new hash to the device */
-	pm_csr = readl(&adapter->regs->global.pm_csr);
+	readl(&adapter->regs->global.pm_csr);
 	if (!et1310_in_phy_coma(adapter)) {
 		writel(hash1, &rxmac->multi_hash1);
 		writel(hash2, &rxmac->multi_hash2);
@@ -999,7 +998,6 @@ static void et1310_setup_device_for_unicast(struct et131x_adapter *adapter)
 	u32 uni_pf1;
 	u32 uni_pf2;
 	u32 uni_pf3;
-	u32 pm_csr;
 
 	/* Set up unicast packet filter reg 3 to be the first two octets of
 	 * the MAC address for both address
@@ -1025,7 +1023,7 @@ static void et1310_setup_device_for_unicast(struct et131x_adapter *adapter)
 		  (adapter->addr[4] << ET_RX_UNI_PF_ADDR1_5_SHIFT) |
 		   adapter->addr[5];
 
-	pm_csr = readl(&adapter->regs->global.pm_csr);
+	readl(&adapter->regs->global.pm_csr);
 	if (!et1310_in_phy_coma(adapter)) {
 		writel(uni_pf1, &rxmac->uni_pf_addr1);
 		writel(uni_pf2, &rxmac->uni_pf_addr2);
@@ -3443,12 +3441,10 @@ static irqreturn_t et131x_isr(int irq, void *dev_id)
 		 * send a pause packet, otherwise just exit
 		 */
 		if (adapter->flow == FLOW_TXONLY || adapter->flow == FLOW_BOTH) {
-			u32 pm_csr;
-
 			/* Tell the device to send a pause packet via the back
 			 * pressure register (bp req and bp xon/xoff)
 			 */
-			pm_csr = readl(&iomem->global.pm_csr);
+			readl(&iomem->global.pm_csr);
 			if (!et1310_in_phy_coma(adapter))
 				writel(3, &iomem->txmac.bp_ctrl);
 		}