abipkgdiff: Do not erase working dirs before we are done using them

abipkgdiff: Do not erase working dirs before we are done using them

	* tools/abipkgdiff.cc (compare_prepared_userspace_packages):
	Removing working directories "early" prevents e.g,
	dwarf_reader::get_soname_of_elf_file from accessing those files.
	So do not remove them until the very end.
	* tests/data/test-diff-pkg/libxcrypt-4.1.1-6.el8.x86_64--libxcrypt-4.1.1-6.el8.x86_64-output-1.txt:
	Adjust.

Signed-off-by: Dodji Seketeli <dodji@redhat.com>