xfsprogs: fix make deb

xfsprogs: fix make deb

Commit 48212a30 ("xfsprogs: update 'make deb' to use tarball) fixed
a bunch of problems with making the source tarball for releases.
However, it broke the debian package builds in a way I hadn't
noticed until I rewrote my CI system build script.

I noticed that the CI system wasn't building from a pristine
workarea, and instead was just updating the old workarea and running
'make deb'. I added a 'make realclean' to remove all previous state
from the workarea, and then 'make deb' started failing with errors
building the tarball because po/xfsprogs.pot didn't have a build
rule

The above commit removed the pre-build of the translations target,
and instead made the translation build target a dependency of
building the the tarball. Hence the lack of a build rule of the
translations causes the source tarball build to fail.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Ben Myers <bpm@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>