QmlProfiler: Don't scan the whole file system in rewriter test

QLibraryInfo::location() returns one string. Iterating over that gives
us the individual characters, beginning with '/'. Running that through
FileName::fromString(), gives us "/", and feeding this to
ModelManagerInterface::importScan() is not funny.

This has to be backported as the sheer volume of files to be scanned
makes the tests time out.

(cherry-picked from commit af8bd12387)
Change-Id: Ib4293437ab83da8ed10a696fba2c30f5c51c8124
Reviewed-by: Eike Ziller <eike.ziller@qt.io>

src/plugins/qmlprofiler/tests/qmlprofilerdetailsrewriter_test.cpp

@@ -213,8 +213,9 @@ void QmlProfilerDetailsRewriterTest::seedRewriter()
 
     QFutureInterface<void> result;
     QmlJS::PathsAndLanguages lPaths;
-    for (auto p : QLibraryInfo::location(QLibraryInfo::Qml2ImportsPath))
-        lPaths.maybeInsert(Utils::FileName::fromString(p), QmlJS::Dialect::Qml);
+    lPaths.maybeInsert(
+                Utils::FileName::fromString(QLibraryInfo::location(QLibraryInfo::Qml2ImportsPath)),
+                QmlJS::Dialect::Qml);
     QmlJS::ModelManagerInterface::importScan(result, QmlJS::ModelManagerInterface::workingCopy(),
                                              lPaths, m_modelManager, false);