Remove unused variables from tests
Fix clang build by removing unused variables and fixing comments
diff --git a/include/mbedtls/ecp.h b/include/mbedtls/ecp.h
index c6e3edb..6bcda17 100644
--- a/include/mbedtls/ecp.h
+++ b/include/mbedtls/ecp.h
@@ -521,7 +521,7 @@
* The output is the group's OID wrapped as ASN.1.
*
* \param grp ECP group used
- * \param buf Buffer to write to
+ * \param p Buffer to write to
* \param size Buffer size
* \param olen Number of bytes written to \c buf
* \return 0 on success