ILocatorFilter: Simplify Sync's onSetup in matchers

Remove no longer necessary bool return value from onSetup
functions and from refresh recipe functions,
see df5e3c587a.

By default, when no return bool is specified inside a function
passed to Sync element, it's assumed that the return value is true.

Eliminate passing "=" captures in 2 lambdas.

Change-Id: I5005821444a386f70c0f05322812f98d3fd49926
Reviewed-by: Marcus Tillmanns <marcus.tillmanns@qt.io>

src/plugins/cmakeprojectmanager/cmakelocatorfilter.cpp

@@ -73,7 +73,6 @@ static LocatorMatcherTasks cmakeMatchers(const CMakeTargetLocatorFilter::BuildAc
             }
         }
         storage->reportOutput(entries);
-        return true;
     };
     return {{Sync(onSetup), storage}};
 }