Fix syscall tampering when PTRACE_GET_SYSCALL_INFO is in use on some architectures

Fix syscall tampering when PTRACE_GET_SYSCALL_INFO is in use on some architectures

When PTRACE_GET_SYSCALL_INFO is in use on those architectures
that invoke set_regs in arch_set_scno, get_regs is not called,
so it has to be invoked explicitly before tampering.

* linux/arc/set_scno.c (arch_set_scno): Explicitly call get_regs
when PTRACE_GET_SYSCALL_INFO is in use.
* linux/avr32/set_scno.c: Likewise.
* linux/csky/set_scno.c: Likewise.
* linux/ia64/set_scno.c: Likewise.
* linux/m68k/set_scno.c: Likewise.
* linux/metag/set_scno.c: Likewise.
* linux/mips/set_scno.c: Likewise.
* linux/nios2/set_scno.c: Likewise.
* linux/or1k/set_scno.c: Likewise.
* linux/riscv/set_scno.c: Likewise.
* linux/s390/set_scno.c: Likewise.
* linux/sparc/set_scno.c: Likewise.
* linux/tile/set_scno.c: Likewise.
* NEWS: Mention this fix.

Thanks-to: Anatoly Pugachev <matorola@gmail.com>
Fixes: v5.2~27 "sparc, sparc64: fix syscall tampering when PTRACE_GET_SYSCALL_INFO is in use"