[PATCH] powerpc/rtas: Use arch_spin_lock instead of arch_spin_lock_flags

[Will Deacon]

arch_spin_lock_flags is an internal part of the spinlock implementation
and is no longer available when SMP=n and DEBUG_SPINLOCK=y, so the PPC
RTAS code fails to compile in this configuration:

   arch/powerpc/kernel/rtas.c: In function 'lock_rtas':
>> arch/powerpc/kernel/rtas.c:81:2: error: implicit declaration of function 
>> 'arch_spin_lock_flags' [-Werror=implicit-function-declaration]
     arch_spin_lock_flags(&rtas.lock, flags);
     ^~~~~~~~~~~~~~~~~~~~

Since there's no good reason to use arch_spin_lock_flags here (the code
in question already calls local_irq_save(flags)), switch it over to
arch_spin_lock and get things building again.

Cc: Peter Zijlstra <pet...@infradead.org>
Reported-by: kbuild test robot <fengguang...@intel.com>
Signed-off-by: Will Deacon <will.dea...@arm.com>
---

This patch fixes build breakage in -next via the -tip tree.

 arch/powerpc/kernel/rtas.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/powerpc/kernel/rtas.c b/arch/powerpc/kernel/rtas.c
index 1643e9e53655..3f1c4fcbe0aa 100644
--- a/arch/powerpc/kernel/rtas.c
+++ b/arch/powerpc/kernel/rtas.c
@@ -78,7 +78,7 @@ static unsigned long lock_rtas(void)
 
        local_irq_save(flags);
        preempt_disable();
-       arch_spin_lock_flags(&rtas.lock, flags);
+       arch_spin_lock(&rtas.lock);
        return flags;
 }
 
-- 
2.1.4