Fixes gcc '-Wunused-but-set-variable' warning:

drivers/platform/x86/classmate-laptop.c: In function cmpc_accel_remove_v4:
drivers/platform/x86/classmate-laptop.c:424:21: warning: variable accel
set but not used [-Wunused-but-set-variable]
drivers/platform/x86/classmate-laptop.c: In function cmpc_accel_remove:
drivers/platform/x86/classmate-laptop.c:660:21: warning: variable accel
set but not used [-Wunused-but-set-variable]

In function cmpc_accel_remove_v4 and cmpc_accel_remove, variable accel is
set but not used, so it can be removed. In that case, variable inputdev is
set but not used and can be removed.

Fixes: 7125587d ("classmate-laptop: Add support for Classmate V4 accelerometer.")
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: yu kuai <yukuai3@huawei.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>