Log Message:
pkgtools/pkglint: update to 19.3.12

Changes since 19.3.11:

The command line option -Wstyle has been removed since it didn't have
any effect.

License names may contain underscores. This fixes 3 parse errors and 2
wrong notes about seemingly unused licenses.

The parser for Makefile variables has been improved for some edge cases.
The :M and :N modifiers behave surprisingly when they contain unbalanced
parentheses or braces. Pkglint now parses them in the same way as bmake,
but doesn't warn since these cases are not actually used in pkgsrc.