str9x: explain compiler that a local variable will always be initialized

Change-Id: I9ddb2793b4cdbf6acea6f69973531491e4ebcc5b
Signed-off-by: Øyvind Harboe <oyvind.harboe@zylin.com>
Reviewed-on: http://openocd.zylin.com/145
Tested-by: jenkins
Reviewed-by: Spencer Oliver <spen@spen-soft.co.uk>

src/flash/nor/str9x.c

@@ -280,6 +280,9 @@ static int str9x_erase(struct flash_bank *bank, int first, int last)
 		total_timeout = 1000;
 	}
 
+	/* this is so the compiler can *know* */
+	assert(total_timeout > 0);
+
 	for (i = first; i <= last; i++)
 	{
 		int retval;