gssapi: gss_krb5_set_allowable_enctypes prototype mismatch

gss_krb5_set_allowable_enctypes() was declared with an array of int32_t types
representing the enctype list, but the definition had an array of krb5_enctype.
Whilst these are likely the same size, they may not be. On the receiving end,
allocate an array of krb5_enctype.

lib/gssapi/mech/gss_krb5.c

@@ -433,7 +433,7 @@ GSSAPI_LIB_FUNCTION OM_uint32 GSSAPI_LIB_CALL
 gss_krb5_set_allowable_enctypes(OM_uint32 *minor_status,
 				gss_cred_id_t cred,
 				OM_uint32 num_enctypes,
-				krb5_enctype *enctypes)
+				int32_t *enctypes)
 {
     krb5_error_code ret;
     OM_uint32 maj_status;