gbuild: avoid leaving invalid .d files behind if build interrupted

The LinkTarget command builds the LinkTarget's dep-file as well as an
optimization so the next make does not restart; in this case the
dep-file is not the target so it will not be deleted by make in case the
build is interrupted, and the next make can choke on the partially
written .d file.

Change-Id: I13b1884f1a974b7ce10b00e1df1d0f30222f4790
scp2: kde module wants to install executables now

Change-Id: I573a48a96061e0d8b30c8e15fb9235df68c4f4e5