xkb: free XkbRulesUsed and XkbRulesDflt on extension cleanup

==2547== 1 bytes in 1 blocks are still reachable in loss record 1 of 111
==2547==    at 0x4C2A4CD: malloc (vg_replace_malloc.c:236)
==2547==    by 0x64D1551: strdup (strdup.c:43)
==2547==    by 0x4802FB: Xstrdup (utils.c:1113)
==2547==    by 0x585B6C: XkbSetRulesUsed (xkbInit.c:219)
==2547==    by 0x58700F: InitKeyboardDeviceStruct (xkbInit.c:595)
==2547==    by 0x419FA3: vfbKeybdProc (InitInput.c:74)
==2547==    by 0x425A3D: ActivateDevice (devices.c:540)
==2547==    by 0x425F65: InitAndStartDevices (devices.c:713)
==2547==    by 0x5ACA57: main (main.c:259)

and a few more of the above.

Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>
Reviewed-by: Keith Packard <keithp@keithp.com>

dix/devices.c

@@ -1052,6 +1052,7 @@ CloseDownDevices(void)
     inputInfo.pointer = NULL;
 
     XkbDeleteRulesDflts();
+    XkbDeleteRulesUsed();
 
     OsReleaseSignals();
 }

include/xkbsrv.h

@@ -751,6 +751,9 @@ extern _X_EXPORT void XkbSetRulesDflts(XkbRMLVOSet *    /* rmlvo */
 extern _X_EXPORT void XkbDeleteRulesDflts(void
     );
 
+extern _X_EXPORT void XkbDeleteRulesUsed(void
+    );
+
 extern _X_EXPORT int SProcXkbDispatch(ClientPtr /* client */
     );
 

xkb/xkbInit.c

@@ -250,6 +250,21 @@ XkbSetRulesDflts(XkbRMLVOSet * rmlvo)
     return;
 }
 
+void
+XkbDeleteRulesUsed(void)
+{
+    free(XkbRulesUsed);
+    XkbRulesUsed = NULL;
+    free(XkbModelUsed);
+    XkbModelUsed = NULL;
+    free(XkbLayoutUsed);
+    XkbLayoutUsed = NULL;
+    free(XkbVariantUsed);
+    XkbVariantUsed = NULL;
+    free(XkbOptionsUsed);
+    XkbOptionsUsed = NULL;
+}
+
 void
 XkbDeleteRulesDflts(void)
 {