ice: Add ice_for_each_vf() macro

Currently we do "for (i = 0; i < pf->num_alloc_vfs; i++)" all over the
place. Many other places use macros to contain this repeated for loop,
So create the macro ice_for_each_vf(pf, i) that does the same thing.

There were a couple places we were using one loop variable and a VF
iterator, which were changed to using a local variable within the
ice_for_each_vf() macro.

Also in ice_alloc_vfs() we were setting pf->num_alloc_vfs after doing
"for (i = 0; i < num_alloc_vfs; i++)". Instead assign pf->num_alloc_vfs
right after allocating memory for the pf->vf array.

Signed-off-by: Brett Creeley <brett.creeley@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>