trace-cmd: Minor cleanup in tracecmd_start_recording()

Initialize `struct timespec req` only once instead of on every loop iteration
since `sleep` is being constant throughout tracecmd_start_recording() execution.

No changes in behavior intended.

Link: http://lore.kernel.org/linux-trace-devel/20190222180539.27439-2-kaslevs@vmware.com

Signed-off-by: Slavomir Kaslev <kaslevs@vmware.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
1 file changed