tools/nolibc: tests: fold in no-stack-protector cflags

For the cflags to enable stack protectors to work properly they need to
be specified after -fno-stack-protector.

To do this fold all cflags into a single variable and move
-fno-stack-protector before the arch-specific cflags and another
one specific to stack protectors since we don't want to enable them
on all archs.

Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>

tools/testing/selftests/nolibc/Makefile

@@ -77,8 +77,9 @@ Q=@
 endif
 
 CFLAGS_s390 = -m64
-CFLAGS  ?= -Os -fno-ident -fno-asynchronous-unwind-tables $(CFLAGS_$(ARCH))
-CFLAGS  += $(call cc-option,-fno-stack-protector)
+CFLAGS  ?= -Os -fno-ident -fno-asynchronous-unwind-tables \
+		$(call cc-option,-fno-stack-protector) \
+		$(CFLAGS_STKP_$(ARCH)) $(CFLAGS_$(ARCH))
 LDFLAGS := -s
 
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