fs: make the buf argument to __kernel_write a void pointer

This matches kernel_read and kernel_write and avoids any need for casts in
the callers.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 0e7d3da8..9ab7e2b 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -2780,7 +2780,7 @@ extern int kernel_read_file_from_fd(int, void **, loff_t *, loff_t,
 				    enum kernel_read_file_id);
 extern ssize_t kernel_read(struct file *, void *, size_t, loff_t *);
 extern ssize_t kernel_write(struct file *, const void *, size_t, loff_t *);
-extern ssize_t __kernel_write(struct file *, const char *, size_t, loff_t *);
+extern ssize_t __kernel_write(struct file *, const void *, size_t, loff_t *);
 extern struct file * open_exec(const char *);
  
 /* fs/dcache.c -- generic fs support functions */