raid: lvcreate and lvchange fail if --min_recovery_rate is defined

raid: lvcreate and lvchange fail if --min_recovery_rate is defined

Both commands default [raid_](min|max)recoveryrate to 0 but ensure
min_recovery_rate is not larger than max_recoveryrate.  This results
in command failure without requestinng the user to also define
max_recovery_rate >= min_recovery_rate.

Fix both commands by defining max_recovery_rate = min_recoveryrate
in case "lvcreate/lvchange --minrecoveryrate Size ..." requests a
larger value than current maxrecoveryrate without also giving option
"--maxrecoveryrate Size ..." with a size greater or equal than min.