selftests/core: remove ARRAY_SIZE define from close_range_test.c

ARRAY_SIZE is defined in several selftests. Remove definitions from
individual test files and include header file for the define instead.
ARRAY_SIZE define is added in a separate patch to prepare for this
change.

Remove ARRAY_SIZE from close_range_test.c and pickup the one defined
in kselftest.h.
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

tools/testing/selftests/core/close_range_test.c

@@ -50,10 +50,6 @@ static inline int sys_close_range(unsigned int fd, unsigned int max_fd,
 	return syscall(__NR_close_range, fd, max_fd, flags);
 }
 
-#ifndef ARRAY_SIZE
-#define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))
-#endif
-
 TEST(core_close_range)
 {
 	int i, ret;