e1000: Removing the unused macro PAGE_USE_COUNT()

Removing the unused macro PAGE_USE_COUNT(), since there is no more reference
to it. The last reference was removed by Jesse's commit number 
630b25cdf4e3f8c0a11eb04fc8436cc36653cd58.

Signed-off-by: Breno Leitao <leitao@linux.vnet.ibm.com>
Acked-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/e1000/e1000_main.c

@@ -1877,8 +1877,6 @@ int e1000_setup_all_rx_resources(struct e1000_adapter *adapter)
  * e1000_setup_rctl - configure the receive control registers
  * @adapter: Board private structure
  **/
-#define PAGE_USE_COUNT(S) (((S) >> PAGE_SHIFT) + \
-			(((S) & (PAGE_SIZE - 1)) ? 1 : 0))
 static void e1000_setup_rctl(struct e1000_adapter *adapter)
 {
 	struct e1000_hw *hw = &adapter->hw;