[packages] olsrd: use system-logger instead of dumping to stdout

packages: olsrd: use system-logger instead of dumping to stdout,
which is cleaner and also seen if not interactive called. minor
cleanups in some messages, also show function-name in messages.
by using 'logger -s' we can see the message on screen and in logs.

Signed-off-by: Bastian Bittorf <bittorf@bluebottle.com>

git-svn-id: svn://svn.openwrt.org/openwrt/packages@35678 3c298f89-4303-0410-b956-a3cf2f4a3e73
[packages] olsrd: don't try to start smartgw if not all deps are installed

[packages] olsrd: don't try to start smartgw if not all deps are installed
if kmod-ipip is missing, there is no need to invoke an expensive operation.

Signed-off-by: Bastian Bittorf <bittorf@bluebottle.com>

git-svn-id: svn://svn.openwrt.org/openwrt/packages@35679 3c298f89-4303-0410-b956-a3cf2f4a3e73
[packages] olsrd: init: cleanup an expensive/forky call

for determining all gateways in all routing tables
1) write out the ip-call, never ever abbreviate in scripts
2) avoid forks: sorting/uniq is not needed, if we only append
   yet unappended words
3) use an extra function() for this, better readable
4) check for installed ip-command

Signed-off-by: Bastian Bittorf <bittorf@bluebottle.com>

git-svn-id: svn://svn.openwrt.org/openwrt/packages@35680 3c298f89-4303-0410-b956-a3cf2f4a3e73