e1000e: cleanup: remove e1000e_commit_phy()

Remove the function e1000e_commit_phy() and replace the few calls to it
with the same function pointer that it would call.  The function pointer is
almost always set for the devices that access these code paths so there is
no risk of a NULL pointer dereference; for the few instances where the
function pointer might not be set (i.e. can be called for the few devices
which do not have this function pointer set), check for a valid function
pointer.

Signed-off-by: Bruce Allan <bruce.w.allan@intel.com>
Tested-by: Jeff Pieper <jeffrey.e.pieper@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>