It has been reported that ubinized nand sysupgrade fails under certain
circumstances, being unable to detach the existing ubi partition due to
volumes within the partition being mounted.
This is an attempt to solve such issues by unmounting and removing
ubiblock devices and unmounting ubi volumes within the target partition
prior to detaching and formatting it.
Signed-off-by: Rodrigo Balerdi <lanchon@gmail.com>
af34733593