syscalls/sendmsg01: using 'ip' command to replace 'ifconfig'

'ip' tools is more general than 'ifconfig', and there are some
distros don't support to install 'ifconfig' tools under default,
which will cause such below error:

   sh: ifconfig: command not found
   sendmsg01    1  TBROK  :  ifconfig failed to bring up loop back device
   sendmsg01    2  TBROK  :  Remaining cases broken

the patch displaced 'ifconfig' using 'ip', and also the case need root
permission and to check capture unexpected signal.

Now, Try 'ip' first and fallback to 'ifconfig' if 'ip' has failed.

Signed-off-by: Zhouping Liu <zliu@redhat.com>
Signed-off-by: Wanlong Gao <gaowanlong@cn.fujitsu.com>