Makefile: remove mandatory "spatch" arguments from SPATCH_FLAGS

The "--patch ." part of SPATCH_FLAGS added in f57d11728d (coccinelle:
put sane filenames into output patches, 2018-07-23) should have been
added unconditionally to the "spatch" invocation instead, using it
isn't optional.

Let's also move the other mandatory flag to come after
$(SPATCH_FLAGS), to ensure that our "--sp-file" overrides any provided
in the environment, both --sp-file <arg> and --patch <arg> are
last-option-wins as far as spatch(1) option parsing is concerned.

The environment variable override was initially added in
a9a884aea5 (coccicheck: use --all-includes by default,
2016-09-30). In practice there's probably nobody that's using
SPATCH_FLAGS to try to intentionally break our invocations, but since
we're changing this let's make it clear what (if anything) we expect
to be overridden by user-supplied flags.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Makefile

@@ -1286,7 +1286,7 @@ SANITIZE_ADDRESS =
 # For the 'coccicheck' target; setting SPATCH_BATCH_SIZE higher will
 # usually result in less CPU usage at the cost of higher peak memory.
 # Setting it to 0 will feed all files in a single spatch invocation.
-SPATCH_FLAGS = --all-includes --patch .
+SPATCH_FLAGS = --all-includes
 SPATCH_BATCH_SIZE = 1
 
 include config.mak.uname
@@ -3131,7 +3131,8 @@ check: $(GENERATED_H)
 		limit='-n $(SPATCH_BATCH_SIZE)'; \
 	fi; \
 	if ! echo $(COCCI_SOURCES) | xargs $$limit \
-		$(SPATCH) --sp-file $< $(SPATCH_FLAGS) \
+		$(SPATCH) $(SPATCH_FLAGS) \
+		--sp-file $< --patch . \
 		>$@+ 2>$@.log; \
 	then \
 		cat $@.log; \