Fix binary reading problem of PCD format

[HTLife]

PCD binary format could look like this:

# .PCD v0.7 - Point Cloud Data file format
VERSION 0.7
FIELDS x y z _ intensity ring _
SIZE 4 4 4 1 4 2 1
TYPE F F F U F U U
COUNT 1 1 1 4 1 1 10
WIDTH 22539
HEIGHT 1
VIEWPOINT 0 0 0 1 0 0 0
POINTS 22539
DATA binary

The correct field size is SIZE * COUNT.

[mrdoob]

Thanks!