net/mlx5: Fix compilation warning in eq.c

mlx5_eq_table_get_rmap is being used only when CONFIG_RFS_ACCEL is
enabled, this patch fixes the below warning when CONFIG_RFS_ACCEL is
disabled.

drivers/.../mlx5/core/eq.c:903:18: [-Werror=missing-prototypes]
error: no previous prototype for ‘mlx5_eq_table_get_rmap’

Fixes: f2f3df5 ("net/mlx5: EQ, Privatize eq_table and friends")
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>

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

@@ -900,14 +900,12 @@ mlx5_comp_irq_get_affinity_mask(struct mlx5_core_dev *dev, int vector)
 }
 EXPORT_SYMBOL(mlx5_comp_irq_get_affinity_mask);
 
+#ifdef CONFIG_RFS_ACCEL
 struct cpu_rmap *mlx5_eq_table_get_rmap(struct mlx5_core_dev *dev)
 {
-#ifdef CONFIG_RFS_ACCEL
 	return dev->priv.eq_table->rmap;
-#else
-	return NULL;
-#endif
 }
+#endif
 
 struct mlx5_eq_comp *mlx5_eqn2comp_eq(struct mlx5_core_dev *dev, int eqn)
 {