Merge pull request contiki-ng#1489 from debug-ito/fix-radio-doc

dev/radio.h: fix some documentation

Author: g-oikonomou

os/dev/radio.h

@@ -97,7 +97,7 @@ typedef unsigned radio_param_t;
  * More specifically, fields prefixed with `RADIO_PARAM_` may be passed as an
  * argument to any of those four functions. Exceptions are documented on a
  * per-field basis. Fields prefixed with `RADIO_CONST_` will only be passed as
- * an argument to `get_value()` and `get_obect()`.
+ * an argument to `get_value()` and `get_object()`.
  */
 enum radio_param_e {
 
@@ -562,7 +562,7 @@ struct radio_driver {
    * `payload` will contain the MAC header (MHR) and MAC payload, but it
    * will _not_ contain the physical header or the MAC footer (MFR).
    *
-   * `payload_len` must be lower than the value retrieved when calling
+   * `payload_len` must be lower than or equal to the value retrieved when calling
    * NETSTACK_RADIO.get_value(RADIO_CONST_MAX_PAYLOAD_LEN, ...)
    *
    * This function will return an error if the radio driver could not copy