net/mlx5: Fix missing return value in mlx5_devlink_eswitch_inline_mode_set()

stable inclusion
from stable-5.10.65
commit 11dd40c18918e7788121d25d23d853f8bf9e1fbc
bugzilla: 182361 https://gitee.com/openeuler/kernel/issues/I4EH3U

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=11dd40c18918e7788121d25d23d853f8bf9e1fbc

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

[ Upstream commit bcd68c04 ]

The return value is missing in this code scenario, add the return value
'0' to the return value 'err'.

Eliminate the follow smatch warning:

drivers/net/ethernet/mellanox/mlx5/core/eswitch_offloads.c:3083
mlx5_devlink_eswitch_inline_mode_set() warn: missing error code 'err'.
Reported-by: NAbaci Robot <abaci@linux.alibaba.com>
Fixes: 8e0aa4bc ("net/mlx5: E-switch, Protect eswitch mode changes")
Signed-off-by: NJiapeng Chong <jiapeng.chong@linux.alibaba.com>
Reviewed-by: NLeon Romanovsky <leonro@nvidia.com>
Signed-off-by: NSaeed Mahameed <saeedm@nvidia.com>
Signed-off-by: NSasha Levin <sashal@kernel.org>
Signed-off-by: NChen Jun <chenjun102@huawei.com>
Acked-by: NWeilong Chen <chenweilong@huawei.com>
Signed-off-by: NChen Jun <chenjun102@huawei.com>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>

drivers/net/ethernet/mellanox/mlx5/core/eswitch_offloads.c

@@ -2564,8 +2564,11 @@ int mlx5_devlink_eswitch_inline_mode_set(struct devlink *devlink, u8 mode,
 
 	switch (MLX5_CAP_ETH(dev, wqe_inline_mode)) {
 	case MLX5_CAP_INLINE_MODE_NOT_REQUIRED:
-		if (mode == DEVLINK_ESWITCH_INLINE_MODE_NONE)
+		if (mode == DEVLINK_ESWITCH_INLINE_MODE_NONE) {
+			err = 0;
 			goto out;
+		}
+
 		fallthrough;
 	case MLX5_CAP_INLINE_MODE_L2:
 		NL_SET_ERR_MSG_MOD(extack, "Inline mode can't be set");