Please pick ("LSM: SafeSetID: Stop releasing uninitialized ruleset") to 5.3 stable

[Doug Anderson]

If you're still taking things for 5.3 stable, I humbly request picking
up commit 21ab8580b383 ("LSM: SafeSetID: Stop releasing uninitialized
ruleset").  While bisecting other problems this crash tripped me up
and I would have been able to bisect faster had the fix been in
linux-stable.  Only kernel 5.3 is affected.

For reference, the crash for me looked like:

Call trace:
 __call_rcu+0x2c/0x1ac
 call_rcu+0x28/0x34
 safesetid_file_write+0x344/0x350
 __vfs_write+0x54/0x18c
 vfs_write+0xcc/0x18c
 ksys_write+0x7c/0xe4
 __arm64_sys_write+0x20/0x2c
 el0_svc_common+0x9c/0x14c
 el0_svc_compat_handler+0x28/0x34
 el0_svc_compat+0x8/0x10

Thanks much.

-Doug