net: rtl8169: Build warning fixes for 64-bit

net: rtl8169: Build warning fixes for 64-bit

Casting from dev->priv to pci_dev_t changes the value's size on a 64-bit
system. This causes the compiler to complain about casting a pointer to an
integer of a different (smaller) size. To avoid this, cast to an integer
of matching size first, then perform an int->int cast to perform the size
change. This signals explicitly that we do want to change the size, and
avoids the compiler warning. This is legitimate since we know the pointer
actually stores a small integer, not a pointer value.

Signed-off-by: Stephen Warren <swarren@nvidia.com>
Acked-by: Joe Hershberger <joe.hershberger@ni.com>