As the possible failure of the allocation, kzalloc() may return NULL
pointer.
Therefore, it should be better to check the 'sgi' in order to prevent
the dereference of NULL pointer.
Fixes: 23ae3a7877 ("net: dsa: felix: add stream gate settings for psfp").
Signed-off-by: Zheng Yongjun <zhengyongjun3@huawei.com>
Reviewed-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Link: https://lore.kernel.org/r/20220329090800.130106-1-zhengyongjun3@huawei.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>