Bug #15948123: SERVER WORKS INCORRECT WITH LONG TABLE ALIASES

After-push cleanup: removal of unneeded assertions.

sql/mdl.h

@@ -246,8 +246,6 @@ class MDL_key
   }
   void mdl_key_init(const MDL_key *rhs)
   {
-    DBUG_ASSERT(rhs->m_length <= NAME_LEN);
-    DBUG_ASSERT(rhs->m_db_name_length <= NAME_LEN);
     memcpy(m_ptr, rhs->m_ptr, rhs->m_length);
     m_length= rhs->m_length;
     m_db_name_length= rhs->m_db_name_length;