Commit 
770cec16cdc9 ("powerpc/audit: Simplify syscall_get_arch()")
and commit 
898a1ef06ad4 ("powerpc/audit: Avoid unneccessary #ifdef
in syscall_get_arguments()")
replaced test_tsk_thread_flag(task, TIF_32BIT)) by is_32bit_task().
But is_32bit_task() applies on current task while be want the test
done on task 'task'
So add a new macro is_tsk_32bit_task() to check any task.
Fixes: 770cec16cdc9 ("powerpc/audit: Simplify syscall_get_arch()")
Fixes: 898a1ef06ad4 ("powerpc/audit: Avoid unneccessary #ifdef in syscall_get_arguments()")
Cc: stable@vger.kernel.org
Reported-by: Dmitry V. Levin <ldv@altlinux.org>
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/c55cddb8f65713bf5859ed675d75a50cb37d5995.1642159570.git.christophe.leroy@csgroup.eu
 
        unsigned long val, mask = -1UL;
        unsigned int n = 6;
 
-       if (is_32bit_task())
+       if (is_tsk_32bit_task(task))
                mask = 0xffffffff;
 
        while (n--) {
 
 static inline int syscall_get_arch(struct task_struct *task)
 {
-       if (is_32bit_task())
+       if (is_tsk_32bit_task(task))
                return AUDIT_ARCH_PPC;
        else if (IS_ENABLED(CONFIG_CPU_LITTLE_ENDIAN))
                return AUDIT_ARCH_PPC64LE;
 
 
 #ifdef CONFIG_COMPAT
 #define is_32bit_task()        (test_thread_flag(TIF_32BIT))
+#define is_tsk_32bit_task(tsk) (test_tsk_thread_flag(tsk, TIF_32BIT))
 #else
 #define is_32bit_task()        (IS_ENABLED(CONFIG_PPC32))
+#define is_tsk_32bit_task(tsk) (IS_ENABLED(CONFIG_PPC32))
 #endif
 
 #if defined(CONFIG_PPC64)