Fix sh4 typo

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
diff --git a/arch/arch-sh.h b/arch/arch-sh.h
index 72183fa..23e6ca0 100644
--- a/arch/arch-sh.h
+++ b/arch/arch-sh.h
@@ -3,7 +3,7 @@
 #ifndef ARCH_SH_H
 #define ARCH_SH_H
 
-#define SH	(arch_sh)
+#define ARCH	(arch_sh)
 
 #ifndef __NR_ioprio_set
 #define __NR_ioprio_set	288