8225101: Crash at sun.awt.X11.XlibWrapper.XkbGetUpdatedMap when change keybord map

Reviewed-by: prr, pbansal

src/solaris/classes/sun/awt/X11/XToolkit.java

@@ -2415,6 +2415,7 @@ public final class XToolkit extends UNIXToolkit implements Runnable {
                  //System.out.println("XkbNewKeyboard:"+(xke.get_new_kbd()));
                  break;
             case XConstants.XkbMapNotify :
+                 if (awt_XKBDescPtr != 0) {
                     //TODO: provide a simple unit test.
                     XlibWrapper.XkbGetUpdatedMap(getDisplay(),
                                                  XConstants.XkbKeyTypesMask    |
@@ -2422,6 +2423,7 @@ public final class XToolkit extends UNIXToolkit implements Runnable {
                                                  XConstants.XkbModifierMapMask |
                                                  XConstants.XkbVirtualModsMask,
                                                  awt_XKBDescPtr);
+                 }
                 //System.out.println("XkbMap:"+(xke.get_map()));
                  break;
             case XConstants.XkbStateNotify :