rgw: Initializes uninitialized members of rgw

rgw: Initializes uninitialized members of rgw

Fixes the coverity issues:

** 1352181 Uninitialized scalar field
2. uninit_member: Non-static class member field fh_hk.bucket is
not initialized in this constructor nor in any functions that it calls.
CID 1352181 (#1 of 1): Uninitialized scalar field (UNINIT_CTOR)
4. uninit_member: Non-static class member field fh_hk.object is
not initialized in this constructor nor in any functions that it calls.

** 1353424 Uninitialized scalar field
CID 1353424 (#1 of 1): Uninitialized scalar field (UNINIT_CTOR)
5. uninit_member: Non-static class member watch_handle is not initialized
 in this constructor nor in any functions that it calls.

** 1355240 Uninitialized scalar field
CID 1355240 (#1 of 1): Uninitialized scalar field (UNINIT_CTOR)
2. uninit_member: Non-static class member index_type is not initialized
in this constructor nor in any functions that it calls.

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