intel_th: msu: Remove set but not used variable 'last'

mainline inclusion
from mainline-v5.3-rc1
commit 9800db28
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I47H3V


CVE: NA

--------------------------------

Commit aad14ad3 ("intel_th: msu: Add current window tracking") added
the following gcc warning:

> drivers/hwtracing/intel_th/msu.c: In function msc_win_switch:
> drivers/hwtracing/intel_th/msu.c:1389:21: warning: variable last set but
> not used [-Wunused-but-set-variable]

Fix it by removing the variable.

Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Fixes: aad14ad3 ("intel_th: msu: Add current window tracking")
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: stable <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20190621161930.60785-3-alexander.shishkin@linux.intel.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Jackie Liu <liuyun01@kylinos.cn>
Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com>
Reviewed-by: Xie XiuQi <xiexiuqi@huawei.com>
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>