[POWERPC] Replace remaining __FUNCTION__ occurrences

__FUNCTION__ is gcc-specific, use __func__

Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>

arch/powerpc/kernel/rtas_flash.c

@@ -807,7 +807,7 @@ int __init rtas_flash_init(void)
 				rtas_block_ctor);
 	if (!flash_block_cache) {
 		printk(KERN_ERR "%s: failed to create block cache\n",
-				__FUNCTION__);
+				__func__);
 		rc = -ENOMEM;
 		goto cleanup;
 	}