The for-loop condition does not work correctly on architectures where
"char" is unsigned. Fix it by using an "int", which may also result in
more efficient code.
Signed-off-by: NDavid Müller <d.mueller@elsoft.ch>
Acked-by: NLarry Finger <Larry.Finger@lwfinger.net>
Signed-off-by: NKalle Valo <kvalo@codeaurora.org>