Makefile: respect $(V) in %.cocci.patch target

When the %.cocci.patch target was defined in 63f0a758a0 (add coccicheck
make target, 2016-09-15), it included a mechanism to suppress the noisy
output, similar to the $(QUIET_<x>) family of variables.

In the case where one wants to inspect the output hidden by
$(QUIET_<x>), one could define $(V) for verbose output. In the
%.cocci.patch target, this was not implemented.

Move the output suppression into the $(QUIET_SPATCH) variable which is
used like the other $(QUIET_<x>) variables. While we're at it, change
the number of spaces printed from 5 to 4, like the other variables
there.

Signed-off-by: Denton Liu <liu.denton@gmail.com>
Acked-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Makefile

@@ -1873,6 +1873,7 @@ ifndef V
 	QUIET_SP       = @echo '   ' SP $<;
 	QUIET_HDR      = @echo '   ' HDR $<;
 	QUIET_RC       = @echo '   ' RC $@;
+	QUIET_SPATCH   = @echo '   ' SPATCH $<;
 	QUIET_SUBDIR0  = +@subdir=
 	QUIET_SUBDIR1  = ;$(NO_SUBDIR) echo '   ' SUBDIR $$subdir; \
 			 $(MAKE) $(PRINT_DIR) -C $$subdir
@@ -2799,7 +2800,7 @@ COCCI_SOURCES = $(filter-out sha1dc/%,$(C_SOURCES))
 endif
 
 %.cocci.patch: %.cocci $(COCCI_SOURCES)
-	@echo '    ' SPATCH $<; \
+	$(QUIET_SPATCH) \
 	if test $(SPATCH_BATCH_SIZE) = 0; then \
 		limit=; \
 	else \