Add a check to make sure the license is actually valid.

portlint.pl

@@ -3224,6 +3224,12 @@ MAINTAINER COMMENT
 			}
 		}
 
+		# Last-ditch check to make sure the license is sanely defined.
+		my $lic_check = system("make check-license 2>&1 >/dev/null");
+		if ($lic_check) {
+			&perror("FATAL", $file, -1, "Failed to validate port LICENSE '$makevar{LICENSE}' with ``make check-license''");
+		}
+
 		$idx++;
 
 		push(@varnames, qw(