powerpc/64s: fix program check interrupt emergency stack path

powerpc/64s: fix program check interrupt emergency stack path

This is an automated ID intended to aid in discovery of potential security vulnerabilities. The actual impact and attack plausibility have not yet been proven.
This ID is fixed in Linux Kernel version v5.10.73 by commit 411b38fe68ba20a8bbe724b0939762c3f16e16ca, it was introduced in version v5.3 by commit 0a882e28468f48ab3d9a36dde0a5723ea29ed1ed. For more details please see the references link.