Revert "sbitmap: Use single per-bitmap counting to wake up queued tags"

This reverts commit 0f312961.

It breaks the ABI right now, but will be brought back at the next ABI
break as it will be needed for Android systems.

Bug: 161946584
Change-Id: Ieeaa94a3768a2b1cd8dcfc97f23e2e1b3404dc57
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>