Fix search highlight matching in some cases.

The attempt at optimizing the loop by skipping the characters that
precede the actual match broke the offset calculations, so the number of
characters skipped in filtering wasn't calculated correctly. Fixit by
removing the misguided optimization.

Example: search for "pera"
highlight in match: Debug non-rectangular cli_p opera_tions
highlight should be: Debug non-rectangular clip o_pera_tions

Change-Id: I07c46b3966e6d81124a5b523c1e822b8750f4f7a