linux-wandboard

[NET]: Fix error reporting in sys_socketpair().

If either of the two sock_alloc_fd() calls fail, we
forget to update 'err' and thus we'll erroneously
return zero in these cases.

Based upon a report and patch from Rich Paul, and
commentary from Chuck Ebbert.

Signed-off-by: David S. Miller <davem@davemloft.net>