igb: fix uninitialized variables

This patch fixes the variable 'phy_word' may be used uninitialized.
Signed-off-by: Yunjian Wang <wangyunjian@huawei.com>
Tested-by: Aaron Brown <aaron.f.brown@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

drivers/net/ethernet/intel/igb/e1000_i210.c

@@ -842,6 +842,7 @@ s32 igb_pll_workaround_i210(struct e1000_hw *hw)
 		nvm_word = E1000_INVM_DEFAULT_AL;
 	tmp_nvm = nvm_word | E1000_INVM_PLL_WO_VAL;
 	igb_write_phy_reg_82580(hw, I347AT4_PAGE_SELECT, E1000_PHY_PLL_FREQ_PAGE);
+	phy_word = E1000_PHY_PLL_UNCONF;
 	for (i = 0; i < E1000_MAX_PLL_TRIES; i++) {
 		/* check current state directly from internal PHY */
 		igb_read_phy_reg_82580(hw, E1000_PHY_PLL_FREQ_REG, &phy_word);