The return value of get_dev_status() can be reused.  Cache it so that
other parts of the kernel can reuse it instead of having to call the
same function again.

Cc: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: NJavi Merino <javi.merino@arm.com>
Signed-off-by: NMyungJoo Ham <myungjoo.ham@samsung.com>