Pass arch/os in probe

Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff --git a/arch/arch-x86_64.h b/arch/arch-x86_64.h
index f2dcf49..29e681f 100644
--- a/arch/arch-x86_64.h
+++ b/arch/arch-x86_64.h
@@ -1,7 +1,7 @@
 #ifndef ARCH_X86_64_h
 #define ARCH_X86_64_h
 
-#define ARCH	(arch_x86_64)
+#define FIO_ARCH	(arch_x86_64)
 
 #ifndef __NR_ioprio_set
 #define __NR_ioprio_set		251