wimax: remove dead code

This removes a code line that is between a "return 0;" and an error label.
This code line can never be reached.

Found by Coverity (CID: 1130529)

Signed-off-by: Michael Opdenacker <michael.opdenacker@free-electrons.com>
Acked-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: David S. Miller <davem@davemloft.net>