is_error_status() is an inline function always called with the
global time_status as an argument, so there's zero functional
difference with this change, but the non-CONFIG_NTP_PPS version
uses the passed-in argument, while the CONFIG_NTP_PPS one ignores
its argument and uses the global.

Looks like is_error_status was refactored out, but someone forgot
to change the logic to check the local argument value.

Thus this patch makes it use the argument always; shorter variable
names are good.
Signed-off-by: NGeorge Spelvin <linux@horizon.com>
[jstultz: Tweaked commit message]
Signed-off-by: NJohn Stultz <john.stultz@linaro.org>