e1000e: cleanup functions that clear hardware statistics

The e1000_clear_hw_cntrs_*() functions read the registers to clear them.
There is no reason to save the register contents so the temp variable can
be removed.

Signed-off-by: Bruce Allan <bruce.w.allan@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/e1000e/lib.c b/drivers/net/e1000e/lib.c
index d173bf8..f690a10 100644
--- a/drivers/net/e1000e/lib.c
+++ b/drivers/net/e1000e/lib.c
@@ -295,45 +295,43 @@
  **/
 void e1000e_clear_hw_cntrs_base(struct e1000_hw *hw)
 {
-	u32 temp;
-
-	temp = er32(CRCERRS);
-	temp = er32(SYMERRS);
-	temp = er32(MPC);
-	temp = er32(SCC);
-	temp = er32(ECOL);
-	temp = er32(MCC);
-	temp = er32(LATECOL);
-	temp = er32(COLC);
-	temp = er32(DC);
-	temp = er32(SEC);
-	temp = er32(RLEC);
-	temp = er32(XONRXC);
-	temp = er32(XONTXC);
-	temp = er32(XOFFRXC);
-	temp = er32(XOFFTXC);
-	temp = er32(FCRUC);
-	temp = er32(GPRC);
-	temp = er32(BPRC);
-	temp = er32(MPRC);
-	temp = er32(GPTC);
-	temp = er32(GORCL);
-	temp = er32(GORCH);
-	temp = er32(GOTCL);
-	temp = er32(GOTCH);
-	temp = er32(RNBC);
-	temp = er32(RUC);
-	temp = er32(RFC);
-	temp = er32(ROC);
-	temp = er32(RJC);
-	temp = er32(TORL);
-	temp = er32(TORH);
-	temp = er32(TOTL);
-	temp = er32(TOTH);
-	temp = er32(TPR);
-	temp = er32(TPT);
-	temp = er32(MPTC);
-	temp = er32(BPTC);
+	er32(CRCERRS);
+	er32(SYMERRS);
+	er32(MPC);
+	er32(SCC);
+	er32(ECOL);
+	er32(MCC);
+	er32(LATECOL);
+	er32(COLC);
+	er32(DC);
+	er32(SEC);
+	er32(RLEC);
+	er32(XONRXC);
+	er32(XONTXC);
+	er32(XOFFRXC);
+	er32(XOFFTXC);
+	er32(FCRUC);
+	er32(GPRC);
+	er32(BPRC);
+	er32(MPRC);
+	er32(GPTC);
+	er32(GORCL);
+	er32(GORCH);
+	er32(GOTCL);
+	er32(GOTCH);
+	er32(RNBC);
+	er32(RUC);
+	er32(RFC);
+	er32(ROC);
+	er32(RJC);
+	er32(TORL);
+	er32(TORH);
+	er32(TOTL);
+	er32(TOTH);
+	er32(TPR);
+	er32(TPT);
+	er32(MPTC);
+	er32(BPTC);
 }
 
 /**