octeon: fix trace for single loop

Type: fix
JIRA: https://essjira.marvell.com/browse/IPBUSW-63189

Change-Id: I67bcb0c4fdc7bed08b42f19e3cd4bbc68fb61dd5
Signed-off-by: Monendra Singh Kushwaha <[email protected]>
Reviewed-on: https://sj1git1.cavium.com/c/IP/SW/toolkits/vpp/+/147750
Tested-by: sa_ip-toolkits-Jenkins <[email protected]>
Reviewed-by: Nithin Kumar Dabilpuram <[email protected]>
(cherry picked from commit 77e2781ce06de12bf03c050b4ef95bd20dcf048d)
Reviewed-on: https://sj1git1.cavium.com/c/IP/SW/toolkits/vpp/+/147791
Tested-by: sa_ip-sw-jenkins <[email protected]>

Author: kmonendra

src/plugins/dev_octeon/rx_node.c

@@ -1014,6 +1014,10 @@ oct_rx_vlib_from_cq (vlib_main_t *vm, oct_nix_rx_cqe_desc_t *d,
   buffs[*buffer_next_index] = b[0];
   next[*buffer_next_index] = ctx->next_index;
   *buffer_next_index = *buffer_next_index + 1;
+
+  if (fp_flags & OCT_FP_FLAG_TRACE_EN)
+    clib_memcpy_fast (b[0]->pre_data, d, sizeof (oct_nix_rx_cqe_desc_t));
+
   return 0;
 }