floss: Ignore wakelock_acquire error in alarm

It's useful for alarm to still behave normally ignoring wakelock_acquire
error, for example in a Linux development environment where the kernel
is not built with /sys/power/wake_lock. Otherwise, some functionalities
may be disturbed due to alarm not behaving normally.

Bug: 204263376
Tag: #floss
Test: Run floss on Linux without /sys/power/wake_lock and exercise
bonding with LE mouse.

Change-Id: I0a419221ef2f2b1463aa89b2812be004360756a7