driver: remove trace_enter()

The kernel has a built-in function tracer, use that instead of rolling
your own.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
driver: remove trace_exit()

No one was using it.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
driver: remove dbgprint and OUTPUT_ macros

No one was using them, so remove them.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
driver: use pr_fmt() instead of hand-coding it

No need to put "sysdig-probe: " in all pr_* functions, let the kernel do
it for you and save memory at the same time.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>