ProjectExplorer: Simplify use of AbstractProcessStep::init()

1. Systematically check for AbstractProcessStep::init() first in
   derived classes.
2. Use setupProcessParameters(processParameters()); by default in
   the base implementation.
3. Drop all re-implementations that are effectively the same.

Change-Id: I0ae54dd4909b354672a63ee56d0b7c2ea0732494
Reviewed-by: Christian Stenger <christian.stenger@qt.io>
Reviewed-by: Christian Kandeler <christian.kandeler@qt.io>

src/plugins/incredibuild/buildconsolebuildstep.cpp

@@ -95,7 +95,6 @@ class BuildConsoleBuildStep : public AbstractProcessStep
 public:
     BuildConsoleBuildStep(BuildStepList *buildStepList, Id id);
 
-    bool init() final;
     void setupOutputFormatter(OutputFormatter *formatter) final;
 };
 
@@ -341,14 +340,6 @@ BuildConsoleBuildStep::BuildConsoleBuildStep(BuildStepList *buildStepList, Id id
     });
 }
 
-bool BuildConsoleBuildStep::init()
-{
-    ProcessParameters *procParams = processParameters();
-    setupProcessParameters(procParams);
-
-    return AbstractProcessStep::init();
-}
-
 void BuildConsoleBuildStep::setupOutputFormatter(OutputFormatter *formatter)
 {
     formatter->addLineParser(new GnuMakeParser());