Fixes bug that sets enabled state for 'Find Next' and 'Find All'
instead of the intended 'Find Previous' and 'Find Next'.

Adds the same enabled state dependency to 'Find All'.

Change-Id: I01d4f0effaa343e1498d9610755b256761dacfd7
Reviewed-on: https://gerrit.libreoffice.org/41264Reviewed-by: Thorsten Behrens <Thorsten.Behrens@CIB.de>
Tested-by: Thorsten Behrens <Thorsten.Behrens@CIB.de>