libbpf: Remove unneeded check for flags during tc detach

mainline inclusion
from mainline-5.14-rc1
commit 4e164f87
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I5EUVD
CVE: NA

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=4e164f8716853b879e2b1a21a12d54c57f11372e

-------------------------------------------------

Coverity complained about this being unreachable code. It is right
because we already enforce flags to be unset, so a check validating
the flag value is redundant.

Fixes: 715c5ce4 ("libbpf: Add low level TC-BPF management API")
Signed-off-by: NKumar Kartikeya Dwivedi <memxor@gmail.com>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20210612023502.1283837-2-memxor@gmail.com
(cherry picked from commit 4e164f87)
Signed-off-by: NWang Yufen <wangyufen@huawei.com>

tools/lib/bpf/netlink.c

@@ -675,8 +675,6 @@ static int __bpf_tc_detach(const struct bpf_tc_hook *hook,
 		return -EINVAL;
 	if (priority > UINT16_MAX)
 		return -EINVAL;
-	if (flags & ~BPF_TC_F_REPLACE)
-		return -EINVAL;
 	if (!flush) {
 		if (!handle || !priority)
 			return -EINVAL;