Bug 579729 – fix XSD schemas parsing crash

* xmlschemas.c: a typo in XSD schema validation, where inherited
  bfminlen rewrote blength and caused SIGSEGV
diff --git a/xmlschemas.c b/xmlschemas.c
index ed3a531..9050684 100644
--- a/xmlschemas.c
+++ b/xmlschemas.c
@@ -17289,7 +17289,7 @@
 	flength = bflength;
     if (flength) {
 	if (! fminlen)
-	    flength = bflength;
+	    fminlen = bfminlen;
 	if (fminlen) {
 	    /* (1.1) length >= minLength */
 	    res = xmlSchemaCompareValues(flength->val, fminlen->val);