evas canvas: fix not to trigger unnecessary events.
Here comparision is logically wrong because it compares
the coordinates(cur, prev) of the different spaces.
As you can see just above the conditions,
Cur coordinates could be transformed into the map space (if objs have)
on the otherhands, prev is not. These wrong condition could occur
embarassing event trigger.
Reviewers: committers, zmike
Reviewed By: committers, zmike
Subscribers: cedric, committers, zmike
Differential Revision: https://phab.enlightenment.org/D6674