lib/iov_iter.c: fix kernel-doc warnings

Fix all kernel-doc warnings in lib/iov_iter.c:

lib/iov_iter.c:695: warning: Function parameter or member 'i' not described in '_copy_mc_to_iter'
lib/iov_iter.c:695: warning: Excess function parameter 'iter' description in '_copy_mc_to_iter'
lib/iov_iter.c:695: warning: No description found for return value of '_copy_mc_to_iter'
lib/iov_iter.c:758: warning: Function parameter or member 'i' not described in '_copy_from_iter_flushcache'
lib/iov_iter.c:758: warning: Excess function parameter 'iter' description in '_copy_from_iter_flushcache'
lib/iov_iter.c:758: warning: No description found for return value of '_copy_from_iter_flushcache'

Link: https://lkml.kernel.org/r/20210809051053.6531-1-rdunlap@infradead.org
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

lib/iov_iter.c

@@ -672,7 +672,7 @@ static size_t copy_mc_pipe_to_iter(const void *addr, size_t bytes,
  * _copy_mc_to_iter - copy to iter with source memory error exception handling
  * @addr: source kernel address
  * @bytes: total transfer length
- * @iter: destination iterator
+ * @i: destination iterator
  *
  * The pmem driver deploys this for the dax operation
  * (dax_copy_to_iter()) for dax reads (bypass page-cache and the
@@ -690,6 +690,8 @@ static size_t copy_mc_pipe_to_iter(const void *addr, size_t bytes,
  * * ITER_KVEC, ITER_PIPE, and ITER_BVEC can return short copies.
  *   Compare to copy_to_iter() where only ITER_IOVEC attempts might return
  *   a short copy.
+ *
+ * Return: number of bytes copied (may be %0)
  */
 size_t _copy_mc_to_iter(const void *addr, size_t bytes, struct iov_iter *i)
 {
@@ -744,7 +746,7 @@ EXPORT_SYMBOL(_copy_from_iter_nocache);
  * _copy_from_iter_flushcache - write destination through cpu cache
  * @addr: destination kernel address
  * @bytes: total transfer length
- * @iter: source iterator
+ * @i: source iterator
  *
  * The pmem driver arranges for filesystem-dax to use this facility via
  * dax_copy_from_iter() for ensuring that writes to persistent memory
@@ -753,6 +755,8 @@ EXPORT_SYMBOL(_copy_from_iter_nocache);
  * all iterator types. The _copy_from_iter_nocache() only attempts to
  * bypass the cache for the ITER_IOVEC case, and on some archs may use
  * instructions that strand dirty-data in the cache.
+ *
+ * Return: number of bytes copied (may be %0)
  */
 size_t _copy_from_iter_flushcache(void *addr, size_t bytes, struct iov_iter *i)
 {