Bug#817147: multipathd is built without systemd support

[Janusz Dziemidowicz]

Package: multipath-tools
Version: 0.5.0+git1.656f8865-5

Recent commit (e91ac62) causes multipathd to be built without systemd
support. This causes multipathd.service unit to fail with timeout,
since it has Type=notify.
The problem is that first an udeb is built, with USE_SYSTEMD=0. Then
the main .deb is built, with USE_SYSTEMD=1, but the second make call
does nothing as the project is already compiled. The result is that
udeb version, without systemd support, is packaged inside .deb

Adding:
$(MAKE) clean
at the end of build-multipath-udeb-stamp target seems to fix the problem.

-- 
Janusz Dziemidowicz