ice: fix stack hogs from struct ice_vsi_ctx structures

struct ice_vsi_ctx has gotten large enough that function local declarations
of it on the stack are causing stack hogs.  Fix that by allocating the
structs on heap.  Cleanup some formatting issues in the code around these
changes and fix incorrect data type uses of returned functions in a couple
places.

Signed-off-by: Bruce Allan <bruce.w.allan@intel.com>
Signed-off-by: Anirudh Venkataramanan <anirudh.venkataramanan@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>