thinkpad_acpi: signedness bugs getting current_mode
thinkpad_acpi: signedness bugs getting current_mode

This needs to be signed for the error handling to work.  Valid modes are
small positive integers.

Fixes: b790ceeb0fd9 ('thinkpad_acpi: Add adaptive_kbd_mode sysfs attr')
Signed-off-by: Dan Carpenter <ff341aa343d564f9e53e9dcb6996be8c04859a66@oracle.com>
Acked-By: Bastien Nocera <f0e564b9407032c2afdab46a63030a8508361337@hadess.net>
Acked-by: Henrique de Moraes Holschuh <1416ae054606eb9be8fa0d7696a4ddff667a3601@hmh.eng.br>
Signed-off-by: Darren Hart <38f9eaa30910c40b06f5a60020b1222f2a953801@linux.intel.com>

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