running queries

Bug#33976: buffer overflow of variable time_buff in function com_go()

An internal buffer was too short.  Overextending could smash the 
stack on some architectures and cause SEGVs.  This is not a problem
that could be exploited to run arbitrary code.

To fix, I expanded one buffer to cover all the size that could be
written to (we know the abolute max).


client/mysql.cc:
  Bump up the max size of the time-elapsed buffer displayed at the end
  of queries.