Fix dividers for LinearLayout (TabWidget)

child.getTop()/child.getLeft - already contains offset for divider height/width,
so we need to subtract it, otherwise divider will be drawn behind the child.

Change-Id: Idd6e5aa4b20e84c64daaefdf393bc00fafb26c45
Signed-off-by: Vladimir Baryshnikov <vovkab@gmail.com>