zebra: add several fields for debug

Two changes for debug:
1. Add a field to indicate its vrf for nexthop.  When the interface changes
vrf, we can't easily know the vrf of this nexthop according to current log.
2. Add a field to indicate operation type.  We can't know whether to add or
remove route according to current log.

Before:
```
zebra_nhg_increment_ref: nhe 0x555623eb82c0 (76[if 6]) 0 => 1
zebra_interface_nhg_reinstall install nhe 75[77.75.1.75 if 6] nh type 3 flags 0x1
Route 77.75.1.0/24(8) queued for processing into sub-queue Early Route Processing
Route 77.75.1.0/24(8) queued for processing into sub-queue Early Route Processing
```

After:
```
zebra_nhg_increment_ref: nhe 0x555623eb82c0 (76[if 6 vrfid 9]) 0 => 1
zebra_interface_nhg_reinstall install nhe 75[77.75.1.75 if 6 vrfid 8] nh type 3 flags 0x1
Route 77.75.1.0/24(8) (add) queued for processing into sub-queue Early Route Processing
Route 77.75.1.0/24(8) (delete) queued for processing into sub-queue Early Route Processing
```

Signed-off-by: anlan_cs <anlan_cs@tom.com>

1 files changed, 2 insertions, 0 deletions

diff --git a/lib/nexthop.c b/lib/nexthop.c
index dcbb76b68e..6b6b0a79c1 100644
--- a/lib/nexthop.c
+++ b/lib/nexthop.c
@@ -932,6 +932,8 @@ ssize_t printfrr_nhs(struct fbuf *buf, const struct nexthop *nexthop)
 		ret += bputs(buf, "blackhole");
 		break;
 	}
+
+	ret += bprintfrr(buf, " vrfid %u", nexthop->vrf_id);
 	return ret;
 }