Staging: rtl8188eu: core: Use list_entry instead of container_of

For variables that have type struct list_head* use list_entry to
access current list element instead of using container_of.
Done using the following semantic patch by coccinelle.

@r@
identifier e;
struct list_head* l;
@@

<... when != l == NULL
l;
...>

(
e=
-container_of
+list_entry
    (
     ...)
)

Signed-off-by: Srishti Sharma <srishtishar@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>