crimson/os: capture local bindings using capture variable list

crimson/os: capture local bindings using capture variable list

structured binding does not define variables, and the implicit
capture-by-copy `=` does not help in this case, we have to define a
capture with an initializer to create a *variable* enclosed by
the closure explicitly.

this address the error like:

src/crimson/os/seastore/segment_cleaner.cc:315:5: error: reference to local binding 'addr' declared in enclosing lambda expression
                  addr);
                  ^

Signed-off-by: Kefu Chai <kchai@redhat.com>