[WATCHDOG] use resource_size()

Use resource_size().

Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Cc: Kevin Hilman <khilman@deeprootsystems.com>
Cc: Kevin Hilman <khilman@ti.deeprootsystems.com>
Cc: Ulrik Bech Hald <ubh@ti.com>
Cc: Henrique de Moraes Holschuh <hmh@hmh.eng.br>
Cc: Ming Lei <tom.leiming@gmail.com>
Cc: Vincent Sanders <support@simtec.co.uk>
Acked-by: Thierry Reding <thierry.reding@avionic-design.de>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/drivers/watchdog/txx9wdt.c b/drivers/watchdog/txx9wdt.c
index 6adab77..d635566 100644
--- a/drivers/watchdog/txx9wdt.c
+++ b/drivers/watchdog/txx9wdt.c
@@ -214,12 +214,10 @@
 	res = platform_get_resource(dev, IORESOURCE_MEM, 0);
 	if (!res)
 		goto exit_busy;
-	if (!devm_request_mem_region(&dev->dev,
-				     res->start, res->end - res->start + 1,
+	if (!devm_request_mem_region(&dev->dev, res->start, resource_size(res),
 				     "txx9wdt"))
 		goto exit_busy;
-	txx9wdt_reg = devm_ioremap(&dev->dev,
-				   res->start, res->end - res->start + 1);
+	txx9wdt_reg = devm_ioremap(&dev->dev, res->start, resource_size(res));
 	if (!txx9wdt_reg)
 		goto exit_busy;