rgw: fix bool/int logic error when calling get_obj_head_ioctx

rgw: fix bool/int logic error when calling get_obj_head_ioctx

get_obj_head_ioctx returns an int where 0 indicates success. When
called in RGWRados::check_disk_state the result was treated as a
booleann with inverted logic. This fixes that error.

This was already fixed in PR #44616 as part of a larger commit, but
this PR unifies the codebase, so various backports are consistent.

This also adds additional logging.

Signed-off-by: J. Eric Ivancich <ivancich@redhat.com>
(cherry picked from commit 28d04e865c1a6d7ef5c2e04727df498380a0b70c)