pl2303: simplify the else-if contruct for type_1 chips in pl2303_startup()

There is no need for two else-if constructs for the type_1 chip
detection in pl2303_startup(), so merge them.

Signed-off-by: Frank Schäfer <fschaefer.oss@googlemail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>