spelling: fix funtion -> function

include/coap2/pdu.h

@@ -467,7 +467,7 @@ int coap_pdu_parse(coap_proto_t proto,
  * Adds token of length @p len to @p pdu.
  * Adding the token destroys any following contents of the pdu. Hence options
  * and data must be added after coap_add_token() has been called. In @p pdu,
- * length is set to @p len + @c 4, and max_delta is set to @c 0. This funtion
+ * length is set to @p len + @c 4, and max_delta is set to @c 0. This function
  * returns @c 0 on error or a value greater than zero on success.
  *
  * @param pdu  The PDU where the token is to be added.

man/coap_logging.txt.in

@@ -57,7 +57,7 @@ Logging by default is to stderr or stdout depending on the logging level of
 the log entry.  It ia possible to send the logging information to an
 application logging call-back handler for processing by the application.
 
-The *coap_log*() funtion is used to log information at the appropriate _level_.
+The *coap_log*() function is used to log information at the appropriate _level_.
 The rest of the parameters follow the standard *printf*() function format.
 
 Logging levels (*coap_log_t*) are defined by (the same as for *syslog*()), which

src/net.c

@@ -1857,7 +1857,7 @@ no_response(coap_pdu_t *request, coap_pdu_t *response) {
       val = coap_decode_var_bytes(coap_opt_value(nores), coap_opt_length(nores));
 
       /* The response should be dropped when the bit corresponding to
-       * the response class is set (cf. table in funtion
+       * the response class is set (cf. table in function
        * documentation). When a No-Response option is present and the
        * bit is not set, the sender explicitly indicates interest in
        * this response. */