Fix typos/style in doxygen documentation
diff --git a/include/mbedtls/net.h b/include/mbedtls/net.h
index 9f757fe..586bd34 100644
--- a/include/mbedtls/net.h
+++ b/include/mbedtls/net.h
@@ -149,7 +149,7 @@
  * \param buf      The buffer to write to
  * \param len      Maximum length of the buffer
  *
- * \return         This function returns the number of bytes received,
+ * \return         the number of bytes received,
  *                 or a non-zero error code; with a non-blocking socket,
  *                 MBEDTLS_ERR_SSL_WANT_READ indicates read() would block.
  */
@@ -163,7 +163,7 @@
  * \param buf      The buffer to read from
  * \param len      The length of the buffer
  *
- * \return         This function returns the number of bytes sent,
+ * \return         the number of bytes sent,
  *                 or a non-zero error code; with a non-blocking socket,
  *                 MBEDTLS_ERR_SSL_WANT_WRITE indicates write() would block.
  */
@@ -179,7 +179,7 @@
  * \param len      Maximum length of the buffer
  * \param timeout  Maximum number of milliseconds to wait for data
  *
- * \return         This function returns the number of bytes received,
+ * \return         the number of bytes received,
  *                 or a non-zero error code:
  *                 MBEDTLS_ERR_SSL_TIMEOUT if the operation timed out,
  *                 MBEDTLS_ERR_SSL_WANT_READ if interrupted by a signal.