Fix duplicate consts around xc_error declarations.

Signed-off-by: Ewan Mellor <ewan@xensource.com>

tools/libxc/xc_private.c

@@ -23,7 +23,7 @@ void xc_default_error_handler(const xc_error const *err)
     fprintf(stderr, "ERROR %s: %s\n", desc, err->message);
 }
 
-const xc_error const *xc_get_last_error(void)
+const xc_error *xc_get_last_error(void)
 {
     return &last_error;
 }

tools/libxc/xenctrl.h

@@ -770,19 +770,19 @@ typedef struct {
  * data pointed to are only valid until the next call to
  * libxc.
  */
-const xc_error const *xc_get_last_error(void);
+const xc_error *xc_get_last_error(void);
 
 /*
  * Clear the last error
  */
 void xc_clear_last_error(void);
 
-typedef void (*xc_error_handler)(const xc_error const* err);
+typedef void (*xc_error_handler)(const xc_error * const err);
 
 /*
  * The default error handler which prints to stderr
  */
-void xc_default_error_handler(const xc_error const* err);
+void xc_default_error_handler(const xc_error * const err);
 
 /*
  * Convert an error code into a text description

tools/python/xen/lowlevel/xc/xc.c

@@ -47,7 +47,7 @@ static PyObject *dom_op(XcObject *self, PyObject *args,
 static PyObject *pyxc_error_to_exception(void)
 {
     PyObject *pyerr;
-    const xc_error const *err = xc_get_last_error();
+    const xc_error *err = xc_get_last_error();
     const char *desc = xc_error_code_to_desc(err->code);
 
     if (err->code == XC_ERROR_NONE)