mei: no need to check return value of debugfs_create functions

When calling debugfs functions, there is no need to ever check the
return value.  The function can work or not, but the code logic should
never do something different based on this.

Cc: Tomas Winkler <tomas.winkler@intel.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/misc/mei/mei_dev.h

@@ -718,13 +718,10 @@ bool mei_hbuf_acquire(struct mei_device *dev);
 bool mei_write_is_idle(struct mei_device *dev);
 
 #if IS_ENABLED(CONFIG_DEBUG_FS)
-int mei_dbgfs_register(struct mei_device *dev, const char *name);
+void mei_dbgfs_register(struct mei_device *dev, const char *name);
 void mei_dbgfs_deregister(struct mei_device *dev);
 #else
-static inline int mei_dbgfs_register(struct mei_device *dev, const char *name)
-{
-	return 0;
-}
+static inline void mei_dbgfs_register(struct mei_device *dev, const char *name) {}
 static inline void mei_dbgfs_deregister(struct mei_device *dev) {}
 #endif /* CONFIG_DEBUG_FS */