Small tweak for random read performance (we shouldn't always tell the OS that...

Small tweak for random read performance (we shouldn't always tell the OS that we will be doing a linear scan). 


sql/examples/ha_tina.cc:
  Small tweak for random read performance.

sql/examples/ha_tina.cc

@@ -609,6 +609,7 @@ int ha_tina::rnd_init(bool scan)
   records= 0;
   chain_ptr= chain;
 #ifdef HAVE_MADVISE
+  if (scan)
     (void)madvise(share->mapped_file,share->file_stat.st_size,MADV_SEQUENTIAL);
 #endif