Impact: Optimization

Like done in inet_unhash(), we can avoid taking a chain lock if
socket is not hashed in udp_unhash()

Triggered by close(socket(AF_INET, SOCK_DGRAM, 0));

Signed-off-by: Eric Dumazet <dada1@cosmosbay.com>
---
 net/ipv4/udp.c |   18 ++++++++++--------
 1 files changed, 10 insertions(+), 8 deletions(-)