e1000/base: return code after setting receive address register

e1000/base: return code after setting receive address register

Previously, the rar_set functions were of type void, and when they failed
to program an address register they would, at most,  put a message into
the log and end.  The fact that they failed to program an address into a
address register, if checked for, should be captured and passed back to
the caller so that the drivers can deal with the situation (or not) as
they deem best.
Drivers can ignore or use the return value.  No change to base drivers
is mandated by this change unless a driver wants to handle the failure
to program an address register (e.g. evaluate the return value).

Signed-off-by: Wenzhuo Lu <wenzhuo.lu@intel.com>