selftests: Set CC using CROSS_COMPILE once in lib.mk

This avoids repeating the logic in every Makefile. We mimic the
top-level Makefile and use $(CROSS_COMPILE)gcc.

Signed-off-by: Michael Ellerman <[e-mail]>
Signed-off-by: Shuah Khan <[e-mail]>

tools/testing/selftests/efivarfs/Makefile

···
-CC = $(CROSS_COMPILE)gcc
 CFLAGS = -Wall
 
 test_objs = open-unlink create-read

tools/testing/selftests/exec/Makefile

···
-CC = $(CROSS_COMPILE)gcc
 CFLAGS = -Wall
 BINARIES = execveat
 DEPS = execveat.symlink execveat.denatured script subdir

tools/testing/selftests/kcmp/Makefile

···
-CC := $(CROSS_COMPILE)$(CC)
 CFLAGS += -I../../../../usr/include/
 
 all: kcmp_test

tools/testing/selftests/lib.mk

···
+# This mimics the top-level Makefile. We do it explicitly here so that this
+# Makefile can operate with or without the kbuild infrastructure.
+CC := $(CROSS_COMPILE)gcc
+
 define RUN_TESTS
 	@for TEST in $(TEST_PROGS); do \
 		(./$$TEST && echo "selftests: $$TEST [PASS]") || echo "selftests: $$TEST [FAIL]"; \

tools/testing/selftests/net/Makefile

···
 # Makefile for net selftests
 
-CC = $(CROSS_COMPILE)gcc
 CFLAGS = -Wall -O2 -g
 
 CFLAGS += -I../../../../usr/include/

tools/testing/selftests/powerpc/Makefile

···
 
 GIT_VERSION = $(shell git describe --always --long --dirty || echo "unknown")
 
-CC := $(CROSS_COMPILE)$(CC)
 CFLAGS := -Wall -O2 -flto -Wall -Werror -DGIT_VERSION='"$(GIT_VERSION)"' -I$(CURDIR) $(CFLAGS)
 
-export CC CFLAGS
+export CFLAGS
 
 TARGETS = pmu copyloops mm tm primitives stringloops
 

tools/testing/selftests/size/Makefile

···
-CC = $(CROSS_COMPILE)gcc
-
 all: get_size
 
 get_size: get_size.c

tools/testing/selftests/vm/Makefile

···
 # Makefile for vm selftests
 
-CC = $(CROSS_COMPILE)gcc
 CFLAGS = -Wall
 BINARIES = hugepage-mmap hugepage-shm map_hugetlb thuge-gen hugetlbfstest
 BINARIES += transhuge-stress