HID: cp2112: fix to force single data-report reply

Current implementation of cp2112_raw_event() only accepts one data report at a
time. If last received data report is not fully handled yet, a new incoming
data report will overwrite it. In such case we don't guaranteed to propagate
the correct incoming data.

The trivial fix implemented here forces a single report at a time by requesting
in cp2112_read() no more than 61 byte of data, which is the payload size of a
single data report.

Cc: stable@vger.kernel.org
Signed-off-by: Antonio Borneo <borneo.antonio@gmail.com>
Tested-by: Ellen Wang <ellen@cumulusnetworks.com>
Signed-off-by: Jiri Kosina <jkosina@suse.com>