Please apply commit 0828137e8f16 ("powerpc/64s: Don't init FSCR_DSCR in __init_FSCR()") to v4.14.y, v4.19.y, v5.4.y, v5.7.y

[Thadeu Lima de Souza Cascardo <cascardo@xxxxxxxxxxxxx>]

After commit 912c0a7f2b5daa3cbb2bc10f303981e493de73bd ("powerpc/64s: Save FSCR
to init_task.thread.fscr after feature init"), which has been applied to the
referred branches, when userspace sets the user DSCR MSR, it won't be inherited
or restored during context switch, because the facility unavailable interrupt
won't trigger.

Applying 0828137e8f16721842468e33df0460044a0c588b ("powerpc/64s: Don't init
FSCR_DSCR in __init_FSCR()") will fix it.

Cascardo.