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>

fs/read_write.c

@@ -487,7 +487,7 @@ ssize_t __vfs_write(struct file *file, const char __user *p, size_t count,
 }
 EXPORT_SYMBOL(__vfs_write);
 
-ssize_t __kernel_write(struct file *file, const char *buf, size_t count, loff_t *pos)
+ssize_t __kernel_write(struct file *file, const void *buf, size_t count, loff_t *pos)
 {
 	mm_segment_t old_fs;
 	const char __user *p;

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 */

kernel/acct.c

@@ -516,7 +516,7 @@ static void do_acct_process(struct bsd_acct_struct *acct)
 	if (file_start_write_trylock(file)) {
 		/* it's been opened O_APPEND, so position is irrelevant */
 		loff_t pos = 0;
-		__kernel_write(file, (char *)&ac, sizeof(acct_t), &pos);
+		__kernel_write(file, &ac, sizeof(acct_t), &pos);
 		file_end_write(file);
 	}
 out: