i915, i965: Fix memory leak in intel_miptree_create_for_bo.

Fixes "Resource leak" defects reported by Coverity.

Signed-off-by: Vinson Lee <vlee@freedesktop.org>
Reviewed-by: Chad Versace <chad.versace@linux.intel.com>

src/mesa/drivers/dri/i915/intel_mipmap_tree.c

@@ -264,8 +264,10 @@ intel_miptree_create_for_bo(struct intel_context *intel,
                                     0, 0,
                                     width, height, 1,
                                     true);
-   if (!mt)
+   if (!mt) {
+      free(region);
       return mt;
+   }
 
    region->cpp = mt->cpp;
    region->width = width;

src/mesa/drivers/dri/i965/intel_mipmap_tree.c

@@ -636,8 +636,10 @@ intel_miptree_create_for_bo(struct brw_context *brw,
                                     0, 0,
                                     width, height, 1,
                                     true, 0 /* num_samples */);
-   if (!mt)
+   if (!mt) {
+      free(region);
       return mt;
+   }
 
    region->cpp = mt->cpp;
    region->width = width;