tools/psim.cc: catch ceph::buffer::end_of_buffer exception

Fix for:

CID 717163 (#1 of 1): Uncaught exception (UNCAUGHT_EXCEPT)
 root_function: In function main(int, char **) an exception of type
 ceph::buffer::end_of_buffer is thrown and never caught.

Signed-off-by: Danny Al-Gaaf <danny.al-gaaf@bisect.de>