Send data to kconsumerd before tracing start

The metadata buffer of the kernel can get overflowed between the start
of the kernel consumer and the kernel start session. Sending the fds
before tracing start fix that problem.

Fixed-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: David Goulet <david.goulet@polymtl.ca>