Bug 581856: Undeprecate {I}TmfCommonXAxisModel.getYSeriesData

Undeprecate this method in these two related types [1,2], as it is still
(genuinely) used within [3], below.

Originally deprecated in commit 843c8f4, since v8.0.0.

[1] o.e.t.tmf.core.model.xy.ITmfCommonXAxisModel.getYSeriesData()
[2] o.e.t.tmf.core.model.TmfCommonXAxisModel.getYSeriesData()
[3] o.e.t.tmf.core.model.xy.TmfTreeXYCompositeDataProvider.fetchXY

Change-Id: Ibbe6a48c9e0646838ac7a36aaf0755cb13f615f1
Signed-off-by: Marco Miller <marco.miller@ericsson.com>
Reviewed-on: https://git.eclipse.org/r/c/tracecompass/org.eclipse.tracecompass/+/201591
Tested-by: Trace Compass Bot <tracecompass-bot@eclipse.org>
Tested-by: Bernd Hufmann <bernd.hufmann@ericsson.com>
Reviewed-by: Bernd Hufmann <bernd.hufmann@ericsson.com>

tmf/org.eclipse.tracecompass.tmf.core/src/org/eclipse/tracecompass/tmf/core/model/TmfCommonXAxisModel.java

@@ -77,12 +77,6 @@ public TmfCommonXAxisModel(String title, long[] xValues, Collection<IYModel> ySe
         return fSeries;
     }
 
-    /**
-     * @deprecated As the former #getXValues() was unused (thus removed), which
-     *             defeats the whole purpose of {@link ITmfCommonXAxisModel}
-     *             including {@link #getYSeriesData()}'s.
-     */
-    @Deprecated
     @Override
     public @NonNull Collection<IYModel> getYSeriesData() {
         return fYSeries;

tmf/org.eclipse.tracecompass.tmf.core/src/org/eclipse/tracecompass/tmf/core/model/xy/ITmfCommonXAxisModel.java

@@ -35,11 +35,7 @@
  *
  * @author Yonni Chen
  * @since 4.0
- * @deprecated As the former #getXValues() was unused (thus removed), at least
- *             in org.eclipse.tracecompass. This defeats the purpose of
- *             {@link #getYSeriesData()} thus this whole interface.
  */
-@Deprecated
 public interface ITmfCommonXAxisModel extends ITmfXyModel {
 
     /**