linux.core: If a thread has no name, mark it as UNKNOWN

Marking threads as " " make them less searchable.

Change-Id: If49921235879d97b6ecdbec86007defd54cb92a6
Signed-off-by: Matthew Khouzam <matthew.khouzam@ericsson.com>
Reviewed-on: https://git.eclipse.org/r/c/tracecompass/org.eclipse.tracecompass/+/204363
Tested-by: Trace Compass Bot <tracecompass-bot@eclipse.org>
Tested-by: Patrick Tasse <patrick.tasse@gmail.com>
Reviewed-by: Patrick Tasse <patrick.tasse@gmail.com>

analysis/org.eclipse.tracecompass.analysis.os.linux.core/src/org/eclipse/tracecompass/analysis/os/linux/core/swslatency/SWSLatencyAnalysis.java

diff --git a/analysis/org.eclipse.tracecompass.analysis.os.linux.core/src/org/eclipse/tracecompass/analysis/os/linux/core/swslatency/SWSLatencyAnalysis.java b/analysis/org.eclipse.tracecompass.analysis.os.linux.core/src/org/eclipse/tracecompass/analysis/os/linux/core/swslatency/SWSLatencyAnalysis.java
index cd1c83c..cccd843 100644
--- a/analysis/org.eclipse.tracecompass.analysis.os.linux.core/src/org/eclipse/tracecompass/analysis/os/linux/core/swslatency/SWSLatencyAnalysis.java
+++ b/analysis/org.eclipse.tracecompass.analysis.os.linux.core/src/org/eclipse/tracecompass/analysis/os/linux/core/swslatency/SWSLatencyAnalysis.java
@@ -120,12 +120,12 @@
                     return;
                 }
 
-                /* Record the event's data into the intial system call info */
+                /* Record the event's data into the initial system call info */
                 long startTime = event.getTimestamp().toNanos();
                 String threadName = event.getContent().getFieldValue(String.class, layout.fieldComm());
 
-                if (threadName == null) {
-                    threadName = ""; //$NON-NLS-1$
+                if (threadName == null || "".equals(threadName)) {
+                    threadName = "UNKNOWN"; //$NON-NLS-1$
                 }
 
                 SchedWS.InitialInfo newSchedWS = new SchedWS.InitialInfo(startTime, threadName.intern(), tid);