selftests/rseq: Change type of rseq_offset to ptrdiff_t

stable inclusion
from stable-v5.10.129
commit d341e5a754803188fa12e1b679b10f53bcd0030a
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I5YNDQ

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=d341e5a754803188fa12e1b679b10f53bcd0030a



--------------------------------

commit 889c5d60 upstream.

Just before the 2.35 release of glibc, the __rseq_offset userspace ABI
was changed from int to ptrdiff_t.

Adapt to this change in the kernel selftests.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://sourceware.org/pipermail/libc-alpha/2022-February/136024.html


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com>
Reviewed-by: Wei Li <liwei391@huawei.com>