* guix/packages.scm (patch-file-name): New procedure.
(%vulnerability-regexp): New variable.
(package-patched-vulnerabilities): New procedure.
* guix/scripts/lint.scm (patch-file-name): Remove.
(check-vulnerabilities): Adjust to use
'package-patched-vulnerabilities'.
* tests/packages.scm ("package-patched-vulnerabilities"): New test.