trace-cmd: Split out binding a port and fork reader from open_udp() Split out binding a port and fork reader from open_udp() for avoiding duplicate codes between listen mode and virt-server mode. Changes in V2: Add a comment in open_udp() Link: http://lkml.kernel.org/r/20130913020630.28927.94339.stgit@yunodevel Signed-off-by: Yoshihiro YUNOMAE <yoshihiro.yunomae.ez@hitachi.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>