QBatteryInfo returns wrong values for currentFlow when battery is in discharging state

QBatteryInfo::currentFlow returns negative values when the battery is discharging even though it should return the flow as positive values in that state.

This was introduced by change id I25b152f99a0ce724cb3ea14533a7a71af42f0827 and might not occur on all linuxes depending on the kernel version.