i40e: handle possible memory allocation failure

The init_interrupt_scheme function had a possible failure
path to allocate memory that was found by smatch.

This adds the correct handling to the function to abort
probe if the memory allocation fails.

Change-ID: I2bf1d826a244209619da4c452d0d58b3eb5e26a3
Signed-off-by: Jesse Brandeburg <jesse.brandeburg@intel.com>
Tested-by: Jim Young <james.m.young@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>