Log Message:
go/go-package.mk: Avoid to print (all) entries in print-PLIST unconditionally

Previously all lines (matching or not /${GO_PLATFORM}/) were printed
unconditionally and could interfere with other PRINT_PLIST_AWKs used by always
printing every line in `print-PLIST' phase.

Avoid that by limiting the pattern of PRINT_PLIST_AWK in go-package.mk.