libvpx

Set rc_2pass_vbr_maxsection_pct to correct value

Corrected a typo that set rc_2pass_vbr_minsection_pct to
two different values on consecutive lines. Second line
should have set rc_2pass_vbr_maxsection_pct.

Change-Id: Ie07ac67cd5455afe556bef34da8127304db9c97c