fuse: handle the case of NULL dereference
fuse: handle the case of NULL dereference

Signed-off-by: Amar Tumballi <amar@gluster.com>
Signed-off-by: Vijay Bellur <vijay@dev.gluster.com>

BUG: 1798 ()
URL: http://bugs.gluster.com/cgi-bin/bugzilla3/show_bug.cgi?id=1798

Kaushikbv/Gluster,Kaushikbv/Gluster,Kaushikbv/Gluster