Kill process correctly in PerforceChecker dtor.

Caused a warning from QProcess when closing Creator right after
start and p4 would time out due to incorrect settings.

Change-Id: I3407d900522f86f12dfedb8c1aeda361017a3e89
Reviewed-on: http://codereview.qt.nokia.com/1884


Reviewed-by: Qt Sanity Bot <qt_sanity_bot@ovi.com>
Reviewed-by: Daniel Teske <daniel.teske@nokia.com>

src/plugins/perforce/perforcechecker.cpp

@@ -61,6 +61,8 @@ PerforceChecker::PerforceChecker(QObject *parent) :
 
 PerforceChecker::~PerforceChecker()
 {
+    m_process.kill();
+    m_process.waitForFinished();
     resetOverrideCursor();
 }