Fix memory leak in 'none' replay cache type

Commit 0f06098e2ab419d02e89a1ca6bc9f2828f6bdb1e fixed part of a memory
leak in the 'none' replay cache type by freeing the outer container,
but we also need to free the mutex.

[ghudson@mit.edu: wrote commit message]

(cherry picked from commit af2a3115cb8feb5174151b4b40223ae45aa9db17)

https://github.com/krb5/krb5/commit/7ef6c40e007a3857ac484fbb14fbad6f5f86d9e9
Author: Corene Casper <C.Casper@Dell.com>
Committer: Greg Hudson <ghudson@mit.edu>
Commit: 7ef6c40e007a3857ac484fbb14fbad6f5f86d9e9
Branch: krb5-1.16
 src/lib/krb5/rcache/rc_none.c |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)