Workaround a kernel race when loading dmcrypt table

The kernel seems to return from umount(2) sometimes before it has
released the underlying block device.  So until the kernel is fixed,
try up to 10 times to load the crypto mapping table, waiting 500 ms
between tries.

bug: 7220345

Change-Id: Iad3bbef37cbe2e01613bb8a8c4886babdecb8328
1 file changed