OMAP: OMAPFB: string parsing cleanups

Use strtobool instead of kstrtoint when parsing bool from sysfs.

Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
diff --git a/drivers/video/omap2/omapfb/omapfb-sysfs.c b/drivers/video/omap2/omapfb/omapfb-sysfs.c
index 153bf1a..1694d51 100644
--- a/drivers/video/omap2/omapfb/omapfb-sysfs.c
+++ b/drivers/video/omap2/omapfb/omapfb-sysfs.c
@@ -104,16 +104,14 @@
 {
 	struct fb_info *fbi = dev_get_drvdata(dev);
 	struct omapfb_info *ofbi = FB2OFB(fbi);
-	int mirror;
+	bool mirror;
 	int r;
 	struct fb_var_screeninfo new_var;
 
-	r = kstrtoint(buf, 0, &mirror);
+	r = strtobool(buf, &mirror);
 	if (r)
 		return r;
 
-	mirror = !!mirror;
-
 	if (!lock_fb_info(fbi))
 		return -ENODEV;