shell: shell_help: fix width for subcommands help text

The terminal offset for subcommands' help text isn't
computed correctly, fix it.

Signed-off-by: Yong Cong Sin <[email protected]>
Signed-off-by: Yong Cong Sin <[email protected]>
(cherry picked from commit fd1be98)

Author: ycsin

subsys/shell/shell_help.c

@@ -110,7 +110,8 @@ static void help_item_print(const struct shell *sh, const char *item_name,
 			    uint16_t item_name_width, const char *item_help)
 {
 	static const uint8_t tabulator[] = "  ";
-	const uint16_t offset = 2 * strlen(tabulator) + item_name_width + 1;
+	static const char sub_cmd_sep[] = ": "; /* subcommands separator */
+	const uint16_t offset = 2 * strlen(tabulator) + item_name_width + strlen(sub_cmd_sep);
 
 	if ((item_name == NULL) || (item_name[0] == '\0')) {
 		return;