libcrypto: fix leak in x509_name_ex_d2i()

[Tobias Heider]

nm.a is initialized to NULL until it gets alloced by x509_name_ex_new().
The following 'goto err' should free nm.a before returning.

ok?

Index: asn1/x_name.c
===================================================================
RCS file: /cvs/src/lib/libcrypto/asn1/x_name.c,v
retrieving revision 1.37
diff -u -p -r1.37 x_name.c
--- asn1/x_name.c       25 Dec 2021 13:17:48 -0000      1.37
+++ asn1/x_name.c       8 Nov 2022 17:45:08 -0000
@@ -340,6 +340,7 @@ x509_name_ex_d2i(ASN1_VALUE **val, const
  err:
        if (nm.x != NULL)
                X509_NAME_free(nm.x);
+       free(nm.a);
        ASN1error(ERR_R_NESTED_ASN1_ERROR);
        return 0;
 }