bus: del unnecessary init var

bus: del unnecessary init var

The compiler generates initialization instructions,
which consume additional CPU cycles. the
sysc_clockdomain_init should assign a value
to 'error' before it is read.so the var don't need init
to 0.

Signed-off-by: Li Jun <lijun01@kylinos.cn>
Link: https://lore.kernel.org/r/20250604081712.119523-1-lijun01@kylinos.cn
Signed-off-by: Kevin Hilman <khilman@baylibre.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>