2 fixes for inclusion into linux-4.19.y

Dear Stable,

Please could you apply the following fixes to the v4.19 Stable tree:

97af84a6bba2 af_unix: Do not use atomic ops for unix_sk(sk)->inflight. 47d8ac011fe1 af_unix: Fix garbage collector racing against connect()

The former was only applied as far back as linux-5.4.y because the commit in the Fixes tag wasn't ever applied to linux-4.19.y, however it is a dependency for the latter, which fixes a real bug also found in linux-4.19.y.

The assumption is that the latter was not applied to linux-4.19.y due to an conflict caused the missing dependency. When both are applied in order, they do so cleanly.

Thank you.

Kind regards, Lee