USB: pl2303: remove 80-columns limit violations in pl2303 driver

Fixes several lines that overrun 80 columns in Prolific pl2303 driver
and cleans up some space usages in the function calls.
Signed-off-by: Thiago Galesi <thiagogalesi@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>