netfilter: nftables: remove redundant assignment of variable err

stable inclusion
from stable-v5.10.140
commit cd962806c4493eec8a0da72d1df227dac28d3e15
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I63FTT

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=cd962806c4493eec8a0da72d1df227dac28d3e15

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

[ Upstream commit 626899a0 ]

The variable err is being assigned a value that is never read,
the same error number is being returned at the error return
path via label err1.  Clean up the code by removing the assignment.

Addresses-Coverity: ("Unused value")
Signed-off-by: NColin Ian King <colin.king@canonical.com>
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: NSasha Levin <sashal@kernel.org>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>
Reviewed-by: NWei Li <liwei391@huawei.com>

net/netfilter/nft_cmp.c

@@ -303,10 +303,8 @@ nft_cmp_select_ops(const struct nft_ctx *ctx, const struct nlattr * const tb[])
 	if (err < 0)
 		return ERR_PTR(err);
 
-	if (desc.type != NFT_DATA_VALUE) {
-		err = -EINVAL;
+	if (desc.type != NFT_DATA_VALUE)
 		goto err1;
-	}
 
 	if (desc.len <= sizeof(u32) && (op == NFT_CMP_EQ || op == NFT_CMP_NEQ))
 		return &nft_cmp_fast_ops;