Don't check pointer we just freed, always set it to NULL.

Signed-off-by: Kurt Roeckx <kurt@roeckx.be>
Reviewed-by: Rich Salz <rsalz@openssl.org>
MR #1231

crypto/asn1/tasn_fre.c

@@ -249,6 +249,5 @@ void asn1_primitive_free(ASN1_VALUE **pval, const ASN1_ITEM *it)
         ASN1_STRING_free((ASN1_STRING *)*pval);
         break;
     }
-    if (*pval)
+    *pval = NULL;
-        *pval = NULL;
 }