rpcsvc: handle NULL deref in case of program mismatch
rpcsvc: handle NULL deref in case of program mismatch

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

BUG: 1982 (rpc: crash on progver mismatch)
URL: http://bugs.gluster.com/cgi-bin/bugzilla3/show_bug.cgi?id=1982

Kaushikbv/Gluster,Kaushikbv/Gluster,Kaushikbv/Gluster