K 10
svn:author
V 8
gallatin
K 8
svn:date
V 27
2018-04-17T12:54:58.968941Z
K 7
svn:log
V 702
Make lagg creation more fault tolerant

- Warn, don't exit, when SIOCSLAGGPORT returns an error.

When we exit with an error during lagg creation, a single
failed NIC (which no longer attaches) can prevent lagg
creation and other configuration, such as adding an IPv4
address, and thus leave a machine unreachable.

- Preserve non-EEXISTS errors for exit status from SIOCSLAGGPORT,
  in case scripts are looking for it. Hopefully this can be
  extended if other parts of ifconfig can allow a "soft" failure.

- Improve the warning message to mention what lagg and what
  member are problematic.

Reviewed by: jtl, glebius
Sponsored by: Netflix
Differential Revision:	https://reviews.freebsd.org/D15046

END