net: dsa: Use sysfs_emit() to instead of sprintf()

Follow the advice of the Documentation/filesystems/sysfs.rst and show()
should only use sysfs_emit() or sysfs_emit_at() when formatting the
value to be returned to user space.
Signed-off-by: Bo Liu <liubo03@inspur.com>
Link: https://lore.kernel.org/r/20230201081438.3151-1-liubo03@inspur.comSigned-off-by: Paolo Abeni <pabeni@redhat.com>

net/dsa/master.c

@@ -299,7 +299,7 @@ static ssize_t tagging_show(struct device *d, struct device_attribute *attr,
 	struct net_device *dev = to_net_dev(d);
 	struct dsa_port *cpu_dp = dev->dsa_ptr;
 
-	return sprintf(buf, "%s\n",
+	return sysfs_emit(buf, "%s\n",
 		       dsa_tag_protocol_to_str(cpu_dp->tag_ops));
 }