rotation: clear pending flag even if don't need to change rotation.
this patch fixes a follows bug.
first, the flag indicated pending rotation was set by un-blocking rotation,
as calling e_zone_rotation_block_set(false). at this moment, if values of curr
and next(e.g. 0) if same, event of zone rotation would not be raised, and
pending flag remains true. in this state, if rotation is changed to different
angle(e.g. 90) by sensord, finally event of zone rotation was raised again with
wrong value(0), because pended rotation was handled again after rotation done
Change-Id: I6579574ec3cf2af00c651999041af4133244e04a