Staging: most: Use list_first_entry instead of list_entry

This patch replaces list_entry with list_first_entry as it makes the
code more clear.
Done using coccinelle:

@@
expression e;
@@
(
- list_entry(e->next,
+ list_first_entry(e,
  ...)
|
- list_entry(e->prev,
+ list_last_entry(e,
  ...)
)

Signed-off-by: Bhumika Goyal <bhumirks@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>