net/mlx5: Fix indir stable stubs

net/mlx5: Fix indir stable stubs

Some of the stubs for CONFIG_MLX5_CLS_ACT==disabled are missing "static
inline" in their definition which causes the following compilation
warnings:

   In file included from drivers/net/ethernet/mellanox/mlx5/core/eswitch_offloads.c:41:
>> drivers/net/ethernet/mellanox/mlx5/core/esw/indir_table.h:34:1: warning: no previous prototype for function 'mlx5_esw_indir_table_init' [-Wmissing-prototypes]
   mlx5_esw_indir_table_init(void)
   ^
   drivers/net/ethernet/mellanox/mlx5/core/esw/indir_table.h:33:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
   struct mlx5_esw_indir_table *
   ^
   static
>> drivers/net/ethernet/mellanox/mlx5/core/esw/indir_table.h:40:1: warning: no previous prototype for function 'mlx5_esw_indir_table_destroy' [-Wmissing-prototypes]
   mlx5_esw_indir_table_destroy(struct mlx5_esw_indir_table *indir)
   ^
   drivers/net/ethernet/mellanox/mlx5/core/esw/indir_table.h:39:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
   void
   ^
   static
>> drivers/net/ethernet/mellanox/mlx5/core/esw/indir_table.h:61:1: warning: no previous prototype for function 'mlx5_esw_indir_table_needed' [-Wmissing-prototypes]
   mlx5_esw_indir_table_needed(struct mlx5_eswitch *esw,
   ^
   drivers/net/ethernet/mellanox/mlx5/core/esw/indir_table.h:60:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
   bool
   ^
   static
   3 warnings generated.

Add "static inline" prefix to signatures of stubs that were missing it.

Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Vlad Buslov <vladbu@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>