ACPI: battery: Remove redundant NULL initalizations

A local 'battery' variable is initialized to NULL on two occassions
where it is unconditionally rewritten later. Remove the unnecessary
initializations.

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://patch.msgid.link/20240731095345.2878-1-ilpo.jarvinen@linux.intel.com


Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>