libparted: link with gnulib

libparted: link with gnulib

* libparted/Makefile.am (libparted_la_LIBADD): Add
$(top_builddir)/lib/libparted.la to the list.
* partprobe/Makefile.am (partprobe_LDADD): Remove now-unneeded
$(top_builddir)/lib/libparted.la.
* libparted/tests/Makefile.am (LDADD): Remove now-unneeded
$(top_builddir)/lib/libparted.la.
* debug/clearfat/Makefile.am (clearfat_LDADD): Likewise.
* parted/Makefile.am (parted_LDADD): Likewise.
Otavio Salvador reported that linking with the resulting shared
library produced an unresolved reference to last_component.