HID: cp2112: fix incorrect error propagation in cp2112_xfer()
HID: cp2112: fix incorrect error propagation in cp2112_xfer()

Both cp2112_read_req() and cp2112_write_req() are returning negative
value in cases of error, but cp2112_xfer() is storing the return
value into unsigned size_t-typed 'count'.

Fix this by making 'count' signed type.

Reported-by: 24f7fe9d205c8a9f6ade0c2894e14303ca16087f@intel.com
Signed-off-by: Jiri Kosina <ed58f755cc8caaf10c3e8c731a8b86fb8f13d6cb@suse.cz>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs