[BUGFIX] Indexed Search: Add missing return statement

Add missing return statement to searchMetaphone() method.

Resolves: #61679
Releases: master, 6.2
Change-Id: Ia87909a3f41fffea4a311c1d682aa97b8d7d5414
Reviewed-on: http://review.typo3.org/32825
Tested-by: Andy Amber <bernstein@barum.de>
Reviewed-by: Markus Klein <klein.t3@reelworx.at>
Tested-by: Markus Klein <klein.t3@reelworx.at>