arm64: fix image size inflation with CONFIG_COMPAT_TASK_SIZE

hulk inclusion
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I8JVJ3


CVE: NA

-------------------------------

Previous patch 605330751290 ("[Huawei] arm64: set 32-bit compatible
TASK_SIZE_MAX to fix U32 libc_write_01 error") has fixed libc_write_01
testcase failed in U32 mode.

However above patch introduced image size inflation when CONFIG_ARM64_ILP32
and CONFIG_AARCH32_EL0 both set. Here fix the problem by testing
current_thread_info()->flags with (_TIF_32BIT | _TIF_32BIT_AARCH64),
rather than calling test_thread_flag() twice.

Fixes: 605330751290 ("[Huawei] arm64: set 32-bit compatible TASK_SIZE_MAX to fix U32 libc_write_01 error")
Signed-off-by: Chen Jiahao <chenjiahao16@huawei.com>
Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com>