crypto-input: fix broken buffer trace issue

crypto-input: fix broken buffer trace issue

dpdk_crypto_input_trace was called before vlib_buffer_enqueue_to_next
then VLIB_FRAME_TRACE of next_frame->flag will be overwritten by
vlib_next_frame_change_ownership(), leading to a broken trace.

now it is working:

Packet 1

00:00:15:654983: dpdk-crypto-input
  dev_id 0 next-index 1
  00:00:15:654999: ip4-lookup
  fib 0 dpo-idx 0 flow hash: 0x00000000
  IPSEC_ESP: 18.1.0.71 -> 18.1.0.241
      tos 0x00, ttl 254, length 168, checksum 0x96ea
......

Change-Id: I73d77c06c11db8911866adb6240b2565b690f469
Signed-off-by: Kingwel Xie <kingwel.xie@ericsson.com>