powerpc/interrupt: Fix CONFIG ifdef typo

CONFIG_PPC_BOOK3S should be CONFIG_PPC_BOOK3S_64. restore_math is a
no-op for other configurations.

Signed-off-by: Christophe Leroy <[email protected]>
[np: split from another patch]
Signed-off-by: Nicholas Piggin <[email protected]>
Signed-off-by: Michael Ellerman <[email protected]>
Link: https://lore.kernel.org/r/[email protected]

Author: chleroy

arch/powerpc/kernel/interrupt.c

@@ -303,7 +303,7 @@ notrace unsigned long syscall_exit_prepare(unsigned long r3,
 		ti_flags = READ_ONCE(current_thread_info()->flags);
 	}
 
-	if (IS_ENABLED(CONFIG_PPC_BOOK3S) && IS_ENABLED(CONFIG_PPC_FPU)) {
+	if (IS_ENABLED(CONFIG_PPC_BOOK3S_64) && IS_ENABLED(CONFIG_PPC_FPU)) {
 		if (IS_ENABLED(CONFIG_PPC_TRANSACTIONAL_MEM) &&
 				unlikely((ti_flags & _TIF_RESTORE_TM))) {
 			restore_tm_state(regs);