debugfs: remove return value of debugfs_create_devm_seqfile()

No one checks the return value of debugfs_create_devm_seqfile(), as it's
not needed, so make the return value void, so that no one tries to do so
in the future.

Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

Documentation/filesystems/debugfs.rst

···
 
 There is a helper function to create device related seq_file::
 
-   struct dentry *debugfs_create_devm_seqfile(struct device *dev,
+   void debugfs_create_devm_seqfile(struct device *dev,
 				const char *name,
 				struct dentry *parent,
 				int (*read_fn)(struct seq_file *s,

fs/debugfs/file.c

···
  *	file will be created in the root of the debugfs filesystem.
  * @read_fn: function pointer called to print the seq_file content.
  */
-struct dentry *debugfs_create_devm_seqfile(struct device *dev, const char *name,
-					   struct dentry *parent,
-					   int (*read_fn)(struct seq_file *s,
-							  void *data))
+void debugfs_create_devm_seqfile(struct device *dev, const char *name,
+				 struct dentry *parent,
+				 int (*read_fn)(struct seq_file *s, void *data))
 {
 	struct debugfs_devm_entry *entry;
 
 	if (IS_ERR(parent))
-		return ERR_PTR(-ENOENT);
+		return;
 
 	entry = devm_kzalloc(dev, sizeof(*entry), GFP_KERNEL);
 	if (!entry)
-		return ERR_PTR(-ENOMEM);
+		return;
 
 	entry->read = read_fn;
 	entry->dev = dev;
 
-	return debugfs_create_file(name, S_IRUGO, parent, entry,
-				   &debugfs_devm_entry_ops);
+	debugfs_create_file(name, S_IRUGO, parent, entry,
+			    &debugfs_devm_entry_ops);
 }
 EXPORT_SYMBOL_GPL(debugfs_create_devm_seqfile);

include/linux/debugfs.h

···
 			      struct dentry *parent,
 			      struct debugfs_u32_array *array);
 
-struct dentry *debugfs_create_devm_seqfile(struct device *dev, const char *name,
-					   struct dentry *parent,
-					   int (*read_fn)(struct seq_file *s,
-							  void *data));
+void debugfs_create_devm_seqfile(struct device *dev, const char *name,
+				 struct dentry *parent,
+				 int (*read_fn)(struct seq_file *s, void *data));
 
 bool debugfs_initialized(void);
 
···
 {
 }
 
-static inline struct dentry *debugfs_create_devm_seqfile(struct device *dev,
-							 const char *name,
-							 struct dentry *parent,
-					   int (*read_fn)(struct seq_file *s,
-							  void *data))
+static inline void debugfs_create_devm_seqfile(struct device *dev,
+					       const char *name,
+					       struct dentry *parent,
+					       int (*read_fn)(struct seq_file *s,
+							      void *data))
 {
-	return ERR_PTR(-ENODEV);
 }
 
 static inline ssize_t debugfs_read_file_bool(struct file *file,