e1000e: fix scheduling while atomic bug

A scheduling while atomic bug was introduced recently (by commit
ce43a216: "e1000e: cleanup USLEEP_RANGE checkpatch checks").

Revert the particular instance of usleep_range() which causes the bug.
Reported-by: Maarten Lankhorst <m.b.lankhorst@gmail.com>
Signed-off-by: Bruce Allan <bruce.w.allan@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/net/ethernet/intel/e1000e/e1000.h

@@ -600,7 +600,7 @@ static inline s32 __ew32_prepare(struct e1000_hw *hw)
 	s32 i = E1000_ICH_FWSM_PCIM2PCI_COUNT;
 
 	while ((er32(FWSM) & E1000_ICH_FWSM_PCIM2PCI) && --i)
-		usleep_range(50, 100);
+		udelay(50);
 
 	return i;
 }