xen/cache-col: Remove bogus cast in domain_llc_coloring_free()

Using:

  xfree(__va(__pa(d->llc_colors)));

is an extraordinarily expensive way of writing:

  xfree((void *)d->llc_colours);

Combined with the comment indicating that this was intention, the patch should
have been rejected outright.

Correct the type of d->llc_colours by removing the bogus const on it, and
remove the cast when freeing it.

No functional change.

Fixes: 6985aa5e0c ("xen: extend domctl interface for cache coloring")
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>

xen/common/llc-coloring.c

@@ -309,11 +309,8 @@ int domain_set_llc_colors(struct domain *d,
 
 void domain_llc_coloring_free(struct domain *d)
 {
-    if ( !llc_coloring_enabled || d->llc_colors == default_colors )
-        return;
-
-    /* free pointer-to-const using __va(__pa()) */
-    xfree(__va(__pa(d->llc_colors)));
+    if ( d->llc_colors != default_colors )
+        xfree(d->llc_colors);
 }
 
 int __init domain_set_llc_colors_from_str(struct domain *d, const char *str)

xen/include/xen/sched.h

@@ -649,7 +649,7 @@ struct domain
 
 #ifdef CONFIG_LLC_COLORING
     unsigned int num_llc_colors;
-    const unsigned int *llc_colors;
+    unsigned int *llc_colors;
 #endif
 
     /* Console settings. */