i40evf: remove unnecessary error checking against i40evf_up_complete

Function i40evf_up_complete() always returns success. Changed this to a
void type and removed the code that checks the return status and prints
an error message.

Change-ID: I8c400f174786b9c855f679e470f35af292fb50ad
Signed-off-by: Bimmy Pujari <bimmy.pujari@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>