omap3: Fix compile for Touch Book early_param

Commit 2b0d8c251b8876d530a6bf671eb5425838fa698a changed ARM to use
the common early_param code. Fix compile for Touch Book accordingly.

Signed-off-by: Tony Lindgren <tony@atomide.com>
diff --git a/arch/arm/mach-omap2/board-omap3touchbook.c b/arch/arm/mach-omap2/board-omap3touchbook.c
index 3943d0f..2a5bf5c 100644
--- a/arch/arm/mach-omap2/board-omap3touchbook.c
+++ b/arch/arm/mach-omap2/board-omap3touchbook.c
@@ -518,14 +518,14 @@
 	gpio_direction_output(TB_KILL_POWER_GPIO, 0);
 }
 
-static void __init early_touchbook_revision(char **p)
+static int __init early_touchbook_revision(char *p)
 {
-	if (!*p)
-		return;
+	if (!p)
+		return 0;
 
-	strict_strtoul(*p, 10, &touchbook_revision);
+	return strict_strtoul(p, 10, &touchbook_revision);
 }
-__early_param("tbr=", early_touchbook_revision);
+early_param("tbr", early_touchbook_revision);
 
 static struct omap_musb_board_data musb_board_data = {
 	.interface_type		= MUSB_INTERFACE_ULPI,