ixgbe: Typecase '1' for 64 bit shift

Make sure we don't get any sign-extend issues when we shift a 1
into bit 31.

Signed-off-by: Shannon Nelson <shannon.nelson@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>