ClangTools: Remove clang executable settings

We use custom clang executable and it does not make
sense anymore to give a choice of changing it.

Change-Id: Icf86042ac3fcd08c320ef2bbdaabef1102b023b5
Reviewed-by: Nikolai Kosjar <nikolai.kosjar@qt.io>

src/plugins/clangtools/clangstaticanalyzerpreconfiguredsessiontests.cpp

@@ -29,6 +29,7 @@
 #include "clangstaticanalyzertool.h"
 #include "clangtoolsutils.h"
 
+#include <cpptools/compileroptionsbuilder.h>
 #include <cpptools/projectinfo.h>
 #include <projectexplorer/kitinformation.h>
 #include <projectexplorer/kitmanager.h>
@@ -166,9 +167,8 @@ static QList<Target *> validTargets(Project *project)
 
         const ToolChain * const toolchain = ToolChainKitInformation::toolChain(kit, ProjectExplorer::Constants::CXX_LANGUAGE_ID);
         QTC_ASSERT(toolchain, return false);
-        bool hasClangExecutable;
-        clangExecutableFromSettings(&hasClangExecutable);
-        if (!hasClangExecutable) {
+
+        if (CppTools::clangExecutable(CLANG_BINDIR).isEmpty()) {
             qWarning("Project \"%s\": Skipping target \"%s\" since no suitable clang was found for the toolchain.",
                      qPrintable(projectFileName),
                      qPrintable(target->displayName()));