rados: Intializing members class StriperTest

rados: Intializing members class StriperTest

Fixes the coverity issue:

** 1221538 Uninitialized pointer field
2. uninit_member: Non-static class member cluster is not initialized
in this constructor nor in any functions that it calls.
4. uninit_member: Non-static class member ioctx is not initialized
in this constructor nor in any functions that it calls.
CID 1221538 (#1 of 1): Uninitialized pointer field (UNINIT_CTOR)
6. uninit_member: Non-static class member striper is not initialized
in this constructor nor in any functions that it calls

Signed-off-by: Amit Kumar amitkuma@redhat.com