debugfs: remove return value of debugfs_create_x8()

No one checks the return value of debugfs_create_x8(), 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/20191011132931.1186197-5-gregkh@linuxfoundation.orgSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Documentation/filesystems/debugfs.txt

@@ -82,8 +82,8 @@ file should not be written to, simply set the mode bits accordingly.  The
 values in these files are in decimal; if hexadecimal is more appropriate,
 the following functions can be used instead:
 
-    struct dentry *debugfs_create_x8(const char *name, umode_t mode,
-				     struct dentry *parent, u8 *value);
+    void debugfs_create_x8(const char *name, umode_t mode,
+			   struct dentry *parent, u8 *value);
     void debugfs_create_x16(const char *name, umode_t mode,
 			    struct dentry *parent, u16 *value);
     void debugfs_create_x32(const char *name, umode_t mode,

fs/debugfs/file.c

@@ -633,10 +633,10 @@ DEFINE_DEBUGFS_ATTRIBUTE(fops_x64_wo, NULL, debugfs_u64_set, "0x%016llx\n");
  * @value: a pointer to the variable that the file should read to and write
  *         from.
  */
-struct dentry *debugfs_create_x8(const char *name, umode_t mode,
-				 struct dentry *parent, u8 *value)
+void debugfs_create_x8(const char *name, umode_t mode, struct dentry *parent,
+		       u8 *value)
 {
-	return debugfs_create_mode_unsafe(name, mode, parent, value, &fops_x8,
+	debugfs_create_mode_unsafe(name, mode, parent, value, &fops_x8,
 				   &fops_x8_ro, &fops_x8_wo);
 }
 EXPORT_SYMBOL_GPL(debugfs_create_x8);

include/linux/debugfs.h

@@ -107,8 +107,8 @@ void debugfs_create_u64(const char *name, umode_t mode, struct dentry *parent,
 			u64 *value);
 struct dentry *debugfs_create_ulong(const char *name, umode_t mode,
 				    struct dentry *parent, unsigned long *value);
-struct dentry *debugfs_create_x8(const char *name, umode_t mode,
-				 struct dentry *parent, u8 *value);
+void debugfs_create_x8(const char *name, umode_t mode, struct dentry *parent,
+		       u8 *value);
 void debugfs_create_x16(const char *name, umode_t mode, struct dentry *parent,
 			u16 *value);
 void debugfs_create_x32(const char *name, umode_t mode, struct dentry *parent,
@@ -268,12 +268,8 @@ static inline struct dentry *debugfs_create_ulong(const char *name,
 	return ERR_PTR(-ENODEV);
 }
 
-static inline struct dentry *debugfs_create_x8(const char *name, umode_t mode,
-					       struct dentry *parent,
-					       u8 *value)
-{
-	return ERR_PTR(-ENODEV);
-}
+static inline void debugfs_create_x8(const char *name, umode_t mode,
+				     struct dentry *parent, u8 *value) { }
 
 static inline void debugfs_create_x16(const char *name, umode_t mode,
 				      struct dentry *parent, u16 *value) { }