Fix compiler warnings in rdopt when warped motion is enabled

The previous code was giving:
 unused variable ‘tmp_rate’ [-Wunused-variable]
 unused variable ‘tmp_dist’ [-Wunused-variable]
 ‘rate2_nocoeff’ may be used uninitialized in this function [-Wmaybe-uninitialized]

Change-Id: I26326d0e5ffc141ad548654356a877cd3627cea6
1 file changed