mutation_test: test_udt_mutations: fix end iterator in call to std::all_of
mutation_test: test_udt_mutations: fix end iterator in call to std::all_of

Signed-off-by: Benny Halevy <23c997c90eb8537635e9392d48e7af1bf1b2ca22@scylladb.com>

avikivity/scylla,scylladb/scylla,avikivity/scylla,scylladb/scylla,avikivity/scylla,scylladb/scylla,scylladb/scylla