Clean up parse_alloc_fields().

Improve parse_alloc_fields()'s readability by switching from strchr() to
strsep() and make sure we have the correct number of fields in the ACE.

Signed-off-by: Johann Dahm <johann.dahm@gmail.com>
Signed-off-by: David M. Richter <richterd@citi.umich.edu>