net: lwm2m: fix max path size

in various places the path can contain leading slash

Signed-off-by: Pascal Brogle <[email protected]>

Author: broglep-work

include/zephyr/net/lwm2m.h

@@ -1398,7 +1398,7 @@ void lwm2m_rd_client_update(void);
 /**
  * @brief LwM2M path maximum length
  */
-#define LWM2M_MAX_PATH_STR_SIZE sizeof("65535/65535/65535/65535")
+#define LWM2M_MAX_PATH_STR_SIZE sizeof("/65535/65535/65535/65535")
 
 /**
  * @brief Helper function to print path objects' contents to log