coccinelle: use $(addsuffix) in 'coccicheck' make target

The dependencies of the 'coccicheck' make target are listed with the
help of the $(patsubst) make function, which in this case doesn't do
any pattern substitution, but only adds the '.patch' suffix.

Use the shorter and more idiomatic $(addsuffix) make function instead.

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

Makefile

@@ -2686,7 +2686,7 @@ C_SOURCES = $(patsubst %.o,%.c,$(C_OBJ))
 	then \
 		echo '    ' SPATCH result: $@; \
 	fi
-coccicheck: $(patsubst %.cocci,%.cocci.patch,$(wildcard contrib/coccinelle/*.cocci))
+coccicheck: $(addsuffix .patch,$(wildcard contrib/coccinelle/*.cocci))
 
 .PHONY: coccicheck