[media] atomisp: one char read beyond end of string

We should verify that "ix < max_len" before we test whether we have
reached the NUL terminator.

Fixes: a49d25364dfb ("staging/atomisp: Add support for the Intel IPU v2")

Reported-by: David Binderman <dcb314@hotmail.com>
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

drivers/staging/media/atomisp/pci/atomisp2/css2400/hive_isp_css_include/string_support.h

@@ -72,9 +72,8 @@ static size_t strnlen_s(
 		return 0;
 	}
 
-	for (ix=0;
-		((src_str[ix] != '\0') && (ix< max_len));
-		++ix) /*Nothing else to do*/;
+	for (ix = 0; ix < max_len && src_str[ix] != '\0'; ix++)
+		;
 
 	/* On Error, it will return src_size == max_len*/
 	return ix;