- Fixed doxygen blocks

diff --git a/include/polarssl/x509.h b/include/polarssl/x509.h
index 32aad72..45a8229 100644
--- a/include/polarssl/x509.h
+++ b/include/polarssl/x509.h
@@ -641,7 +641,7 @@
  */
 const char *x509_oid_get_description( x509_buf *oid );
 
-/*
+/**
  * \brief          Give an OID, return a string version of its OID number.
  *
  * \param buf      Buffer to write to