xkb: Clean up warnings

Add const to lots of strings.

Signed-off-by: Keith Packard <keithp@keithp.com>
Reviewed-by: Adam Jackson <ajax@redhat.com>

include/xkbrules.h

@@ -64,7 +64,7 @@ typedef struct _XkbRF_Rule {
 typedef struct _XkbRF_Group {
     int number;
     const char *name;
-    const char *words;
+    char *words;
 } XkbRF_GroupRec, *XkbRF_GroupPtr;
 
 #define	XkbRF_PendingMatch	(1L<<1)

include/xkbsrv.h

@@ -852,7 +852,7 @@ extern _X_EXPORT unsigned int XkbDDXLoadKeymapByNames(DeviceIntPtr /* keybd */ ,
     );
 
 extern _X_EXPORT Bool XkbDDXNamesFromRules(DeviceIntPtr /* keybd */ ,
-                                           char * /* rules */ ,
+                                           const char * /* rules */ ,
                                            XkbRF_VarDefsPtr /* defs */ ,
                                            XkbComponentNamesPtr /* names */
     );