tests/test-diff-copy-depth.out

doc/Makefile: Don't show Makefile comments in output

The comments makes sense when editing Makefile, but not when watching its
output where it looks too much like error messages.

-- With aaa
Status:
A somename
  other-file

Diff:
diff --git a/other-file b/somename
copy from other-file
copy to somename

-- With zzz
Status:
A somename
  other-file

Diff:
diff --git a/other-file b/somename
copy from other-file
copy to somename