netfilter: don't use mutex_lock_interruptible()

netfilter: don't use mutex_lock_interruptible()

Eric Dumazet reports that getsockopt() or setsockopt() sometimes
returns -EINTR instead of -ENOPROTOOPT, causing headaches to
application developers.

This patch replaces all the mutex_lock_interruptible() by mutex_lock()
in the netfilter tree, as there is no reason we should sleep for a
long time there.

Reported-by: Eric Dumazet <[email protected]>
Suggested-by: Patrick McHardy <[email protected]>
Signed-off-by: Pablo Neira Ayuso <[email protected]>
Acked-by: Julian Anastasov <[email protected]>