coccinelle: extract dedicated make target to clean Coccinelle's results

Sometimes I want to remove only Coccinelle's results, but keep all
other build artifacts left after my usual 'make all man' build.  This
new 'cocciclean' make target will allow just that.

Signed-off-by: SZEDER Gábor <szeder.dev@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Makefile

@@ -2906,7 +2906,10 @@ profile-clean:
 	$(RM) $(addsuffix *.gcda,$(addprefix $(PROFILE_DIR)/, $(object_dirs)))
 	$(RM) $(addsuffix *.gcno,$(addprefix $(PROFILE_DIR)/, $(object_dirs)))
 
-clean: profile-clean coverage-clean
+cocciclean:
+	$(RM) contrib/coccinelle/*.cocci.patch*
+
+clean: profile-clean coverage-clean cocciclean
 	$(RM) *.res
 	$(RM) $(OBJECTS)
 	$(RM) $(LIB_FILE) $(XDIFF_LIB) $(VCSSVN_LIB)
@@ -2918,7 +2921,6 @@ clean: profile-clean coverage-clean
 	$(RM) -r $(GIT_TARNAME) .doc-tmp-dir
 	$(RM) $(GIT_TARNAME).tar.gz git-core_$(GIT_VERSION)-*.tar.gz
 	$(RM) $(htmldocs).tar.gz $(manpages).tar.gz
-	$(RM) contrib/coccinelle/*.cocci.patch*
 	$(MAKE) -C Documentation/ clean
 ifndef NO_PERL
 	$(MAKE) -C gitweb clean
@@ -2934,7 +2936,7 @@ endif
 	$(RM) GIT-USER-AGENT GIT-PREFIX
 	$(RM) GIT-SCRIPT-DEFINES GIT-PERL-DEFINES GIT-PERL-HEADER GIT-PYTHON-VARS
 
-.PHONY: all install profile-clean clean strip
+.PHONY: all install profile-clean cocciclean clean strip
 .PHONY: shell_compatibility_test please_set_SHELL_PATH_to_a_more_modern_shell
 .PHONY: FORCE cscope