Qt5: Correct usage of testlib.

This corrects commit 112f80. $$QTESTLIB is not needed since both Qt4 and
Qt5 support "QT += testlib".

Change-Id: I776b44825295c86d2d85e9b8dc6a422da6f36ab6
Reviewed-by: Christian Stenger <christian.stenger@digia.com>

qtcreator.pri

@@ -72,8 +72,6 @@ defineTest(minQtVersion) {
 
 isEqual(QT_MAJOR_VERSION, 5) {
 
-QTESTLIB = testlib
-
 # For use in custom compilers which just copy files
 defineReplace(stripSrcDir) {
     return($$relative_path($$absolute_path($$1, $$OUT_PWD), $$_PRO_FILE_PWD_))
@@ -81,8 +79,6 @@ defineReplace(stripSrcDir) {
 
 } else { # qt5
 
-QTESTLIB = qtestlib
-
 # For use in custom compilers which just copy files
 win32:i_flag = i
 defineReplace(stripSrcDir) {

tests/auto/icheckbuild/icheckbuild.pro

@@ -4,7 +4,7 @@ include(../../../qtcreator.pri)
 include($$IDE_SOURCE_TREE/src/libs/cplusplus/cplusplus.pri)
 include($$IDE_SOURCE_TREE/src/plugins/cpptools/cpptools.pri)
 
-QT += $$QTESTLIB
+QT += testlib
 
 DEFINES += ICHECK_BUILD ICHECK_APP_BUILD
 

tests/auto/qml/qmldesigner/bauhaustests/bauhaustests.pro

 include(../../../../../qtcreator.pri)
 #include(../../../../../src/plugins/qmldesigner/config.pri)
-QT += $$QTESTLIB
+QT += testlib
 CONFIG += testcase
 
 ##DEFINES += DONT_MESS_WITH_QDEBUG

tests/auto/qml/qmldesigner/propertyeditortests/propertyeditortests.pro

 include(../../../../../qtcreator.pri)
 TEMPLATE = app
-QT += script declarative webkit $$QTESTLIB
+QT += script declarative webkit testlib
 CONFIG += testcase
 CONFIG += console
 CONFIG -= app_bundle

tests/auto/qml/qmleditor/qmllookup/qmllookup.pro

 include(../../../../../qtcreator.pri)
 TEMPLATE = app
-QT += $$QTESTLIB
+QT += testlib
 CONFIG += qt warn_on console depend_includepath testcase
 include(../../../../../src/libs/qmljs/qmljs-lib.pri)
 DEFINES += QML_BUILD_STATIC_LIB

tests/auto/qttest.pri

@@ -2,7 +2,7 @@ include(../../qtcreator.pri)
 include(qttestrpath.pri)
 
 isEmpty(TEMPLATE):TEMPLATE=app
-QT += $$QTESTLIB
+QT += testlib
 CONFIG += qt warn_on console depend_includepath testcase
 CONFIG -= app_bundle