Reinstate detection of inappropriate uevent with DISK_RO set and suppress it.

Reinstate detection of inappropriate uevent with DISK_RO set and suppress it.

We still need to detect this one! We're not so strict with CHANGE events as
with the ADD events while applying filters in the rules so this one would
pass and it would process the rules prematurely (because it appears *before*
the actual CHANGE event used when resuming a DM device while setting read-only
state at the same time).