staging: vme_user: Use list_for_each_entry() helper

Convert list_for_each() to list_for_each_entry() so that the
slave/master/dma/handler/lm_pos list_head pointer and list_entry()
call are no longer needed, which can reduce a few lines
of code. No functional changed.

Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com>
Link: https://lore.kernel.org/r/20230823071437.450460-1-ruanjinjie@huawei.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>