Fixed doxygen blocks
(cherry picked from commit 77db6ce3481ad610ee786d5ab171d5d10c1cb59d)
diff --git a/include/polarssl/xtea.h b/include/polarssl/xtea.h
index e2adb87..0db7bc8 100644
--- a/include/polarssl/xtea.h
+++ b/include/polarssl/xtea.h
@@ -97,7 +97,7 @@
                     unsigned char *input,
                     unsigned char *output);
 
-/*
+/**
  * \brief          Checkup routine
  *
  * \return         0 if successful, or 1 if the test failed