10132 smatch fixes for MDB
Reviewed by: Andy Fiddaman <andy@omniosce.org>

*** 1988,1998 ****
          *equals = '=';
  
          (void) mdb_nv_insert(&pt->p_env, name, NULL, (uintptr_t)val,
              MDB_NV_EXTNAME);
  
-         if (equals)
                  *equals = '=';
  }
  
  /*
   * Clears the internal environment.
--- 1988,1997 ----