libsubcmd: Move EXTRA_FLAGS to the end to allow overriding existing flags

Move EXTRA_WARNINGS and EXTRA_FLAGS to the end of the compilation line,
otherwise they cannot be used to override the default values.
Signed-off-by: James Clark <james.clark@arm.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: James Clark <james.clark@arm.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: nd <nd@arm.com>
Link: http://lore.kernel.org/lkml/20191028113340.4282-1-james.clark@arm.com
[ split from a larger patch ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/lib/subcmd/Makefile

@@ -19,8 +19,7 @@ MAKEFLAGS += --no-print-directory
 
 LIBFILE = $(OUTPUT)libsubcmd.a
 
-CFLAGS := $(EXTRA_WARNINGS) $(EXTRA_CFLAGS)
-CFLAGS += -ggdb3 -Wall -Wextra -std=gnu99 -fPIC
+CFLAGS := -ggdb3 -Wall -Wextra -std=gnu99 -fPIC
 
 ifeq ($(DEBUG),0)
   ifeq ($(feature-fortify-source), 1)
@@ -43,6 +42,8 @@ CFLAGS += -D_LARGEFILE64_SOURCE -D_FILE_OFFSET_BITS=64 -D_GNU_SOURCE
 
 CFLAGS += -I$(srctree)/tools/include/
 
+CFLAGS += $(EXTRA_WARNINGS) $(EXTRA_CFLAGS)
+
 SUBCMD_IN := $(OUTPUT)libsubcmd-in.o
 
 all: