seq_file: fix new kernel-doc warnings

Fix kernel-doc warnings in fs/seq_file.c:

  Warning(fs/seq_file.c:304): No description found for parameter 'whence'
  Warning(fs/seq_file.c:304): Excess function parameter 'origin' description in 'seq_lseek'
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

fs/seq_file.c

@@ -296,7 +296,7 @@ EXPORT_SYMBOL(seq_read);
  *	seq_lseek -	->llseek() method for sequential files.
  *	@file: the file in question
  *	@offset: new position
- *	@origin: 0 for absolute, 1 for relative position
+ *	@whence: 0 for absolute, 1 for relative position
  *
  *	Ready-made ->f_op->llseek()
  */