Makefile: don't try to clean old debian build product

The 'clean' target includes code to remove an '*.tar.gz' file that
was the by-product of a debian build. This was originally added by
commit 5a571cdd8a (Clean generated files a bit more, to cope with
Debian build droppings., 2005-08-12). However, all support for the
'debian build' was dropped by commit 7d0e65b892 (Retire debian/
directory., 2006-01-06), which seems to have simply forgotten to
remove the 'git-core_$(GIT_VERSION)-*.tar.gz' from the 'clean'
target. Remove it now.

Signed-off-by: Ramsay Jones <ramsay@ramsayjones.plus.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Makefile

@@ -3159,7 +3159,7 @@ clean: profile-clean coverage-clean cocciclean
 	$(RM) -r po/build/
 	$(RM) *.pyc *.pyo */*.pyc */*.pyo $(GENERATED_H) $(ETAGS_TARGET) tags cscope*
 	$(RM) -r $(GIT_TARNAME) .doc-tmp-dir
-	$(RM) $(GIT_TARNAME).tar.gz git-core_$(GIT_VERSION)-*.tar.gz
+	$(RM) $(GIT_TARNAME).tar.gz
 	$(RM) $(htmldocs).tar.gz $(manpages).tar.gz
 	$(MAKE) -C Documentation/ clean
 	$(RM) Documentation/GIT-EXCLUDED-PROGRAMS