protcol/server: server_connection_destroy - destroy frame after issuing flush
protcol/server: server_connection_destroy - destroy frame after issuing flush

frame was getting destroyed after unlocking, but before issuing flush. This
could result in corruption if an fd was opened between server_connection_cleanup
and server_connection_destroy because of pending open calls in io-threads at the
time of POLLERR disconnection

Signed-off-by: Anand V. Avati <avati@blackhole.gluster.com>
Signed-off-by: Anand V. Avati <avati@dev.gluster.com>

BUG: 430 (Server crash when client is killed)
URL: http://bugs.gluster.com/cgi-bin/bugzilla3/show_bug.cgi?id=430

Kaushikbv/Gluster,Kaushikbv/Gluster,Kaushikbv/Gluster