net/e1000: Fix EEPROM access error

Commit 951860634f may have changed
the logic unintentially from "if (!(swfw_sync & (fwmask | swmask)))"
to "if ((swfw_sync & swmask) && !(swfw_sync & fwmask))". This change
breaks some e1000 NIC with a message "ERROR: Unable to read EEPROM!".

Signed-off-by: York Sun <yorksun@freescale.com>
CC: Marek Vasut <marex@denx.de>
CC: Tim Harvey <tharvey@gateworks.com>
Acked-by: Marcel Ziswiler <marcel@ziswiler.com>

drivers/net/e1000.c

@@ -1113,7 +1113,7 @@ e1000_swfw_sync_acquire(struct e1000_hw *hw, uint16_t mask)
 			return -E1000_ERR_SWFW_SYNC;
 
 		swfw_sync = E1000_READ_REG(hw, SW_FW_SYNC);
-		if ((swfw_sync & swmask) && !(swfw_sync & fwmask))
+		if (!(swfw_sync & (fwmask | swmask)))
 			break;
 
 		/* firmware currently using resource (fwmask) */