At least on tinderbox MacOSX-x86_64@49-TDF the sed appears to ignore the
literal newline character, which is unfortunate, particularly since it
worked on the Jenkins builder.

Blind fix to replace this with a tr invocation that already appears to
work in Zip.mk.

Change-Id: I7a77e69774b050a018b12c73ddd9eff849c33a86