RDMA/mlx5: Remove two unused declarations

Commit e6fb246ccafb ("RDMA/mlx5: Consolidate MR destruction to
mlx5_ib_dereg_mr()") removed mlx5_ib_free_implicit_mr() but left
the declaration.

Commit d98995b4bf98 ("net/mlx5: Reimplement write combining test") left
mlx5_ib_test_wc().

Remove the unused declarations.

Link: https://patch.msgid.link/r/[e-mail]
Signed-off-by: Yue Haibing <[e-mail]>
Signed-off-by: Jason Gunthorpe <[e-mail]>

drivers/infiniband/hw/mlx5/mlx5_ib.h

···
 int mlx5_ib_dealloc_mw(struct ib_mw *mw);
 struct mlx5_ib_mr *mlx5_ib_alloc_implicit_mr(struct mlx5_ib_pd *pd,
 					     int access_flags);
-void mlx5_ib_free_implicit_mr(struct mlx5_ib_mr *mr);
 void mlx5_ib_free_odp_mr(struct mlx5_ib_mr *mr);
 struct ib_mr *mlx5_ib_rereg_user_mr(struct ib_mr *ib_mr, int flags, u64 start,
 				    u64 length, u64 virt_addr, int access_flags,
···
 	mlx5r_deref_odp_mkey(mmkey);
 	wait_event(mmkey->wait, refcount_read(&mmkey->usecount) == 0);
 }
-
-int mlx5_ib_test_wc(struct mlx5_ib_dev *dev);
 
 static inline bool mlx5_ib_lag_should_assign_affinity(struct mlx5_ib_dev *dev)
 {