UPSTREAM: ANDROID: binder: correct the cmd print for BINDER_WORK_RETURN_ERROR

When to execute binder_stat_br the e->cmd has been modifying as BR_OK
instead of the original return error cmd, in fact we want to know the
original return error, such as BR_DEAD_REPLY or BR_FAILED_REPLY, etc.
instead of always BR_OK, in order to avoid the value of the e->cmd is
always BR_OK, so we need assign the value of the e->cmd to cmd before
e->cmd = BR_OK.

Signed-off-by: songjinshi <songjinshi@xiaomi.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
(cherry picked from commit 838d5565669aa5bb7deb605684a5970d51d5eaf6)

Change-Id: I425b32c5419a491c6b9ceee7c00dde6513e0421d