ARM: 9147/1: add printf format attribute to early_print()

Adding such an attribute is helpful to detect errors related to printf
formats at compile-time.

Link: https://lore.kernel.org/r/20160828165815.25647-1-nicolas.iooss_linux@m4x.org

Signed-off-by: Nicolas Iooss <nicolas.iooss_linux@m4x.org>
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>

arch/arm/include/asm/setup.h

@@ -19,7 +19,7 @@
 static const struct tagtable __tagtable_##fn __tag = { tag, fn }
 
 extern int arm_add_memory(u64 start, u64 size);
-extern void early_print(const char *str, ...);
+extern __printf(1, 2) void early_print(const char *str, ...);
 extern void dump_machine_table(void);
 
 #ifdef CONFIG_ATAGS_PROC