e1000e: cleanup: remove unnecessary variable ret_val

ret_val gets initialized to -E1000_ERR_NVM and never set differently, so
get rid of it and just return -E1000_ERR_NVM.
Signed-off-by: NBruce Allan <bruce.w.allan@intel.com>
Tested-by: NAaron Brown <aaron.f.brown@intel.com>
Signed-off-by: NJeff Kirsher <jeffrey.t.kirsher@intel.com>

drivers/net/ethernet/intel/e1000e/ich8lan.c

@@ -2308,7 +2308,6 @@ static s32 e1000_flash_cycle_ich8lan(struct e1000_hw *hw, u32 timeout)
 {
 	union ich8_hws_flash_ctrl hsflctl;
 	union ich8_hws_flash_status hsfsts;
-	s32 ret_val = -E1000_ERR_NVM;
 	u32 i = 0;
 
 	/* Start a cycle by writing 1 in Flash Cycle Go in Hw Flash Control */
@@ -2327,7 +2326,7 @@ static s32 e1000_flash_cycle_ich8lan(struct e1000_hw *hw, u32 timeout)
 	if (hsfsts.hsf_status.flcdone == 1 && hsfsts.hsf_status.flcerr == 0)
 		return 0;
 
-	return ret_val;
+	return -E1000_ERR_NVM;
 }
 
 /**