* Serialize ops in acpi_cmbat_notify_handler(), acpi_cmbat_ioctl(),
acpi_cmbat_init_battery(), and acpi_cmbat_get_battinfo().
* Get the softc directly in acpi_cmbat_get_total_battinfo() rather than
build an array of them.
* Don't queue a _BIF query after receiving a notify. Since we clear the
timespec, a _BIF query will be done in the context of the next caller.
* Add asserts to leaf functions that operate on shared data.
* Remove the bst/bif updating flags now that we hold the lock over the
full query.
* Explain various comments in more detail.