bonding_err_ does not correctly parse kernel 3.0 output

[zugschlus]

This is Debian Bug #648686

The patch proposed by the reporter (against svn head) is attached.

[wferi]

Fixing this would also fix #1026.
Using sed also makes it possible to avoid grep and cut (for performance) like this:

sed "0,/^Slave Interface: ${if}/d; /^\$/,\$d; s/^Link Failure Count: //;t;d" ${PROCDIR}/${BONDINGIF}