seccomp-util: add lsm_get_self_attr and lsm_list_modules to @default

These syscalls are part of a newer kernel API to replace interaction
with /proc/self/attr, with the goal of allowing LSM stacking. These are
being used now by e.g. libapparmor, so should be more easily available
to services using seccomp filtering.

src/shared/seccomp-util.c

@@ -402,6 +402,8 @@ const SyscallFilterSet syscall_filter_sets[_SYSCALL_FILTER_SET_MAX] = {
                 "gettimeofday\0"
                 "getuid\0"
                 "getuid32\0"
+                "lsm_get_self_attr\0"
+                "lsm_list_modules\0"
                 "membarrier\0"
                 "mmap\0"
                 "mmap2\0"