this fixes two bugs in Hyper-V VM ignition handling:
1. Changed `err := readAndSplitIgnition()` to
`err = readAndSplitIgnition()` so the deferred cleanup function can
properly detect errors and clean up ignition
2. The function was trying to remove keys with pattern `vm.ElementName + index`, but
the actual keys were created using `"ignition.config." + index` pattern.
It also improve the deletion by calculating in how many parts the ignition file is splitted when being added in the registry and delete just them instead of blidnly iterating through 0-50.
Signed-off-by: lstocchi <lstocchi@redhat.com>
cfa1b51775