net/mlx5: Fix return type mismatch in mlx5_esw_vport_vhca_id()

net/mlx5: Fix return type mismatch in mlx5_esw_vport_vhca_id()

The function mlx5_esw_vport_vhca_id() is declared to return bool,
but returns -EOPNOTSUPP (-45), which is an int error code. This
causes a signedness bug as reported by smatch.

This patch fixes this smatch report:
drivers/net/ethernet/mellanox/mlx5/core/eswitch.h:981 mlx5_esw_vport_vhca_id()
warn: signedness bug returning '(-45)'

Fixes: 1baf30426553 ("net/mlx5: E-Switch, Set/Query hca cap via vhca id")
Reviewed-by: Parav Pandit <parav@nvidia.com>
Signed-off-by: Zeng Chi <zengchi@kylinos.cn>
Reviewed-by: Tariq Toukan <tariqt@nvidia.com>
Link: https://patch.msgid.link/20260123085749.1401969-1-zeng_chi911@163.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>