Update to v5.22.0-RC2-1-gdfd03a6.

Cleanup a bit the PKGNAMESUFFIX calculation.
Also force the PERL_PORT variable for the -devel one, in case there is more
than one with the same version.

Changes: https://github.com/Perl/perl5/compare/v5.22.0-RC1...v5.22.0-RC2-1-gdfd03a6
Sponsored by: Absolight