staging/lustre: remove Peng Tao from Lustre contact list

I am leaving emc for a new company where I cannot have much
time working on Lustre. So remove myself from the contact
list. I will still be around and continue to contribute as a
hobbyist though.

Cc: Andreas Dilger <andreas.dilger@intel.com>
Cc: Oleg Drokin <oleg.drokin@intel.com>
Signed-off-by: Peng Tao <bergwolf@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>