install: Fix possible overflow condition in the updater "scanner"

Don't just reset the position pointer after a failure, reset it
after a successful match too, to prevent a followup loop from poking
beyond the limit of the match arrays. (if matchmeta is hit before
matchperm)

Change-Id: I7842798597eb1aee79b4c770f1eeca131020483d
Merge remote-tracking branch 'cm/cm-11.0' into cm-11.0