selinux: policydb - rename type_val_to_struct_array

The name is overly long and inconsistent with the other *_val_to_struct
members. Dropping the "_array" prefix makes the code easier to read and
gets rid of one line over 80 characters warning.

Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>