[PATCH 10/36] cmd/libsnap-confine-private: Fix use of uninitialised variable

[PATCH 10/36] cmd/libsnap-confine-private: Fix use of uninitialised variable

Ensure xdg_runtime_dir_env is zero initialisd in
sc_call_snap_update_ns_as_user() otherwise when XDG_RUNTIME_DIR is not
defined the uninitialised contents of this buffer will be passed to
snap-update-ns. This is unlikely to be an issue in practice as
snap-update-ns is quite defensive in terms of environment variable handing
already.

Signed-off-by: Alex Murray <alex.murray@canonical.com>
Gbp-Pq: Topic cve202144730
Gbp-Pq: Name 0010-cmd-libsnap-confine-private-Fix-use-of-uninitialised.patch