net: hns3: fix wrong judgment condition issue

driver inclusion
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I8MWM5


CVE: NA

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In hns3_dcbnl_ieee_delapp, should check ieee_delapp not ieee_setapp.
This path fix the wrong judgment.

Fixes: 7a1313b3 ("net: hns3: add support config dscp map to tc")
Signed-off-by: Jijie Shao <shaojijie@huawei.com>