kp_transport: Use percpu print_buffer to fix stack over-usage message

Use percpu print_buffer for kp_printf to fix stack over-usage message.
Usually, the perf event handler is called where the stack is already
consumed (it could be called from deepest one). Thus, we should avoid
using the stack.
This introduce print_buffer per-cpu data structure for the buffers
for cpu-local scnprintf.

Signed-off-by: Masami Hiramatsu <masami.hiramatsu@gmail.com>
ktapio: Check output error in reader thread

Check output error in reader thread. If there is an error
it just quit.

Signed-off-by: Masami Hiramatsu <masami.hiramatsu@gmail.com>
Support perf probe for setting kprobe event
eventdef: Allow kprobe event to specify types

Allow kprobe event to specify types which separated
by ':' in argument.
eventdef: Fix to support perf tools