Support automatic kprobe event detection in common case

Support automatic kprobe event detection in common case

* In the simple case, a user only creates 1 C function to be used with
  kprobes. Detect this common case and don't require the user to repeat
  themselves by passing the fn_name to attach_kprobe().
  e.g.: BPF(text='int sys_clone(void *ctx) {/*do stuff*/}').trace_print()

Signed-off-by: Brenden Blanco <bblanco@plumgrid.com>