netconsole: Include sysdata in extradata entry count

Modify count_extradata_entries() to include sysdata fields when
calculating the total number of extradata entries. This change ensures
that the sysdata feature, specifically the CPU number field, is
correctly counted against the MAX_EXTRADATA_ITEMS limit.

The modification adds a simple check for the CPU_NR flag in the
sysdata_fields, incrementing the entry count accordingly.

Signed-off-by: Breno Leitao <leitao@debian.org>
Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

Author: leitao

drivers/net/netconsole.c

@@ -694,7 +694,15 @@ static ssize_t remote_ip_store(struct config_item *item, const char *buf,
  */
 static size_t count_extradata_entries(struct netconsole_target *nt)
 {
-	return list_count_nodes(&nt->userdata_group.cg_children);
+	size_t entries;
+
+	/* Userdata entries */
+	entries = list_count_nodes(&nt->userdata_group.cg_children);
+	/* Plus sysdata entries */
+	if (nt->sysdata_fields & CPU_NR)
+		entries += 1;
+
+	return entries;
 }
 
 static ssize_t remote_mac_store(struct config_item *item, const char *buf,