assuan: Use exponential decay for first 1s of spinlock.
* common/asshelp.c (wait_for_sock): instead of checking the socket every second, we check 10 times in the first second (with exponential decay).
This cuts the wall clock time for the standard test suite roughly by
(cherry picked from commit 149041b0b917f4298239fe18b5ebd5ead71584a6)
- GnuPG-bug-id: T3490
- Signed-off-by: Daniel Kahn Gillmor <email@example.com>