ipx: fix ipx_release()

Commit b0d0d915 (remove the BKL) added a regression, because
sock_put() can free memory while we are going to use it later.

Fix is to delay sock_put() _after_ release_sock().

Reported-by: Ingo Molnar <mingo@elte.hu>
Tested-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: David S. Miller <davem@davemloft.net>