CTF: Fix channel naming

This was erroniously removed in a previous change.

Pick-to: 6.6 6.5
Change-Id: Ia62327bea7e3d190503a0eb05217c0f780f4fe9a
Reviewed-by: Antti Määttä <antti.maatta@qt.io>

src/plugins/tracing/qctflib.cpp

@@ -379,6 +379,7 @@ void QCtfLibImpl::doTracepoint(const QCtfTracePointEvent &point, const QByteArra
         ch.impl = this;
         m_channels.append(&ch);
         m_threadIndices.insert(thread, m_threadIndices.size());
+        sprintf(ch.channelName, "%s/channel_%d", qPrintable(m_location), m_threadIndices[thread]);
         ch.minTimestamp = ch.maxTimestamp = timestamp;
         ch.thread = thread;
         ch.threadIndex = m_threadIndices[thread];