net/mlx5: SF, Fix return type

Fix the following coccicheck warnings:

drivers/net/ethernet/mellanox/mlx5/core/sf/dev/dev.h:50:8-9: WARNING:
return of 0/1 in function 'mlx5_sf_dev_allocated' with return type bool
Signed-off-by: Roi Dayan <roid@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>

drivers/net/ethernet/mellanox/mlx5/core/sf/dev/dev.h

@@ -47,7 +47,7 @@ static inline void mlx5_sf_driver_unregister(void)
 
 static inline bool mlx5_sf_dev_allocated(const struct mlx5_core_dev *dev)
 {
-	return 0;
+	return false;
 }
 
 #endif