xdiff/xprepare: use the XDF_DIFF_ALG() macro to access flag bits

Commit 307ab20b3 ("xdiff: PATIENCE/HISTOGRAM are not independent option bits", 19-02-2012) introduced the XDF_DIFF_ALG() macro to access the flag bits used to represent the diff algorithm requested. In addition, code which had used explicit manipulation of the flag bits was changed to use the macros.

However, one example of direct manipulation remains. Update this code to use the XDF_DIFF_ALG() macro.

---
 xdiff/xprepare.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

index 63a22c6..5ffcf99 100644
@@ -304,7 +304,7 @@ int xdl_prepare_env(mmfile_t *mf1, mmfile_t *mf2, xpparam_t const *xpp,
 		return -1;
 	}
 
-	if (!(xpp->flags & XDF_HISTOGRAM_DIFF))
+	if (XDF_DIFF_ALG(xpp->flags) != XDF_HISTOGRAM_DIFF)
 		xdl_free_classifier(&cf);
 
 	return 0;

2.7.0