osd: Initializing start_offset,last_offset,offset
Fixes the coverity issues:
2. uninit_member: Non-static class member start_offset
is not initialized in this constructor nor in any functions
that it calls.
CID
1424396 (#1 of 1): Uninitialized scalar field (UNINIT_CTOR)
4. uninit_member: Non-static class member last_offset is not
initialized in this constructor nor in any functions that it calls.
CID
1424658 (#1 of 1): Uninitialized scalar field (UNINIT_CTOR)
2. uninit_member: Non-static class member offset is not initialized
in this constructor nor in any functions that it calls.
Signed-off-by: Amit Kumar <amitkuma@redhat.com>