clocksource/driver/arm_global_timer: Remove unnecessary ‘0’ values from err

The 'err' variable is initialized whatever the code path, it is
pointless to initialize it when it is declared.

Signed-off-by: Li kunyu <kunyu@nfschina.com>
Link: https://lore.kernel.org/r/20240705052159.22235-1-kunyu@nfschina.com


Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>