table results in table corrupt

Fulltext key has always two keysegs, thus we need to update
FT_SEGS (last) element from seg array in case of compressed table.
Also we must update ft2_keyinfo.


myisam/mi_packrec.c:
  Fulltext key has always two keysegs, thus we need to update
  FT_SEGS (last) element from seg array in case of compressed table.
  Also we must update ft2_keyinfo.