watchdog: dw_wdt: Staticize local symbol

'dw_wdt_write' is used only in this file. Make it static.
Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>

drivers/watchdog/dw_wdt.c

@@ -154,8 +154,8 @@ static int dw_wdt_open(struct inode *inode, struct file *filp)
 	return nonseekable_open(inode, filp);
 }
 
-ssize_t dw_wdt_write(struct file *filp, const char __user *buf, size_t len,
-		     loff_t *offset)
+static ssize_t dw_wdt_write(struct file *filp, const char __user *buf,
+			    size_t len, loff_t *offset)
 {
 	if (!len)
 		return 0;