sandbox: Use const in os_jump_to_file()

The argument array is not changed by the callee, so mark it const.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Mattijs Korpershoek <mkorpershoek@baylibre.com>
diff --git a/arch/sandbox/cpu/os.c b/arch/sandbox/cpu/os.c
index 46ff305..a04eb5a 100644
--- a/arch/sandbox/cpu/os.c
+++ b/arch/sandbox/cpu/os.c
@@ -808,7 +808,7 @@
  * @count: Number of arguments in @add_args
  * Return: 0 if OK, -ENOMEM if out of memory
  */
-static int add_args(char ***argvp, char *add_args[], int count)
+static int add_args(char ***argvp, const char *add_args[], int count)
 {
 	char **argv, **ap;
 	int argc;
@@ -859,7 +859,7 @@
 	struct sandbox_state *state = state_get_current();
 	char mem_fname[30];
 	int fd, err;
-	char *extra_args[5];
+	const char *extra_args[5];
 	char **argv = state->argv;
 	int argc;
 #ifdef DEBUG