net: hns3: refine the input parameter 'size' for snprintf()

net: hns3: refine the input parameter 'size' for snprintf()

The function snprintf() writes at most size bytes (including the
terminating null byte ('\0') to str. Now, We can guarantee that the
parameter of size is lager than the length of str to be formatting
including its terminating null byte. So it's unnecessary to minus 1
for the input parameter 'size'.

Signed-off-by: Guojia Liao <liaoguojia@huawei.com>
Signed-off-by: Huazhong Tan <tanhuazhong@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>