powerpc/interrupt: Rename and lightly change syscall_exit_prepare_main()

Rename syscall_exit_prepare_main() into interrupt_exit_prepare_main()

Pass it the 'ret' so that it can 'or' it directly instead of
oring twice, once inside the function and once outside.

And remove 'r3' parameter which is not used.
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
[np: split out some changes into other patches]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210617155116.2167984-14-npiggin@gmail.com

arch/powerpc/kernel/interrupt.c

@@ -243,11 +243,10 @@ static notrace void booke_load_dbcr0(void)
 #endif
 }
 
-static notrace unsigned long syscall_exit_prepare_main(unsigned long r3,
-						       struct pt_regs *regs)
+static notrace unsigned long
+interrupt_exit_user_prepare_main(unsigned long ret, struct pt_regs *regs)
 {
 	unsigned long ti_flags;
-	unsigned long ret = 0;
 
 again:
 	ti_flags = READ_ONCE(current_thread_info()->flags);
@@ -365,7 +364,7 @@ notrace unsigned long syscall_exit_prepare(unsigned long r3,
 	}
 
 	local_irq_disable();
-	ret |= syscall_exit_prepare_main(r3, regs);
+	ret = interrupt_exit_user_prepare_main(ret, regs);
 
 #ifdef CONFIG_PPC64
 	regs->exit_result = ret;
@@ -397,7 +396,7 @@ notrace unsigned long syscall_exit_restart(unsigned long r3, struct pt_regs *reg
 
 	BUG_ON(!user_mode(regs));
 
-	regs->exit_result |= syscall_exit_prepare_main(r3, regs);
+	regs->exit_result = interrupt_exit_user_prepare_main(regs->exit_result, regs);
 
 	return regs->exit_result;
 }