staging: rdma: amso1100: Remove unnecessary variables

Remove unnecessary variable 'err' from functions c2_reject() and
c2_service_destroy() since it can be replaced by a single line of
code instead.

Signed-off-by: Amitoj Kaur Chawla <amitoj1606@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>