net: rbridge: replace nested ifs with goto -> failur

Signed-off-by: François Cachereul <f.cachereul@alphalink.fr>
Signed-off-by: William Dauchy <william@gandi.net>
net: rbridge: use consistent error codes instead of EFAULT

Signed-off-by: François Cachereul <f.cachereul@alphalink.fr>
Signed-off-by: William Dauchy <william@gandi.net>
net: rbridge: fix possible memleaks an null pointer derefs

Sending TRILL_CMD_GET_NICKS_INFO command with an unknown nickname
cause a NULL pointer dereference.

Signed-off-by: François Cachereul <f.cachereul@alphalink.fr>
Signed-off-by: William Dauchy <william@gandi.net>
Signed-off-by: Ahmed Amamou <ahmed@gandi.net>
net: rbridge: code cleanup

- remove a useless global variable
- put all attribut policies in a unique table

Signed-off-by: François Cachereul <f.cachereul@alphalink.fr>
Signed-off-by: William Dauchy <william@gandi.net>