Improve some errors for openconsole/channel
Functions like virDomainOpenConsole() and virDomainOpenChannel() accept
NULL as a dev_name parameter. Try using alias for the error message if
dev_name is not specified.
Before:
error: internal error: character device <null> is not using a PTY
After:
error: internal error: character device serial0 is not using a PTY
Signed-off-by: Luyao Huang <lhuang@redhat.com>