powerpc/audit: Avoid unneccessary #ifdef in syscall_get_arguments()

Use is_32bit_task() which already handles CONFIG_COMPAT.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/ba49cdd574558a0363300c3f6b5b062b397cb071.1629451483.git.christophe.leroy@csgroup.eu

arch/powerpc/include/asm/syscall.h

@@ -90,10 +90,9 @@ static inline void syscall_get_arguments(struct task_struct *task,
 	unsigned long val, mask = -1UL;
 	unsigned int n = 6;
 
-#ifdef CONFIG_COMPAT
-	if (test_tsk_thread_flag(task, TIF_32BIT))
+	if (is_32bit_task())
 		mask = 0xffffffff;
-#endif
+
 	while (n--) {
 		if (n == 0)
 			val = regs->orig_gpr3;