ASoC: Intel: Skylake: Remove driver debugfs exit

For driver debugfs, debugfs_remove_recursive() is called which is not
needed as it is already done in ASoC core debugfs. And a device managed
memory need not be freed explicitly as device core frees it up. So
remove unnecessary skl_debugfs_exit().

Fixes: 5cdf6c09ca ASoC: ("Intel: Skylake: Add debugfs support")
Reported-by: Julia Lawall <julia.lawall@lip6.fr>
Reported-by: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
Signed-off-by: Guneshwor Singh <guneshwor.o.singh@intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

sound/soc/intel/skylake/skl.h

@@ -125,7 +125,6 @@ struct skl_module_cfg;
 
 #ifdef CONFIG_DEBUG_FS
 struct skl_debug *skl_debugfs_init(struct skl *skl);
-void skl_debugfs_exit(struct skl_debug *d);
 void skl_debug_init_module(struct skl_debug *d,
 			struct snd_soc_dapm_widget *w,
 			struct skl_module_cfg *mconfig);
@@ -134,8 +133,6 @@ static inline struct skl_debug *skl_debugfs_init(struct skl *skl)
 {
 	return NULL;
 }
-static inline void skl_debugfs_exit(struct skl_debug *d)
-{}
 static inline void skl_debug_init_module(struct skl_debug *d,
 					 struct snd_soc_dapm_widget *w,
 					 struct skl_module_cfg *mconfig)