Fix assert when blend time is 0.
Fix assert when blend time is 0.

Jump straight to the target value when blend time
is 0. Don't try to blend from current to target value
in 0 time.

Change-Id: I04280447b714e0ed8992c6ba95d5be0fb4ee45f8
Tested: Fix assert on OSX.

google/motive,google/motive