read.

Do not store profiling information when there is no query text.  We
don't wish to capture non-COM_QUERY packets.


sql/sql_parse.cc:
  Start profiling immediately after a command packet is read from 
  the network.
sql/sql_profile.cc:
  Do not store items for which there is no query, i.e., protocol API 
  calls (non-COM_QUERY) and such.