net/irda: add missing error path release_sock call

commit 896ee0eee6261e30c3623be931c3f621428947df upstream.

This makes sure that release_sock is called for all error conditions in
irda_getsockopt.

Signed-off-by: Kees Cook <keescook@chromium.org>
Reported-by: Brad Spengler <spender@grsecurity.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>