arm, i386: switch back to use PTRACE_GETREGS

PTRACE_GETREGSET and PTRACE_GETREGS methods are equally good on arm and
i386 architectures, but PTRACE_GETREGSET with fallback to PTRACE_GETREGS
is a bit more costly, so choose the method that costs less.
This partially reverts commit v4.7-149-gfaa177e.

* syscall.c [ARM, I386] (ARCH_REGS_FOR_GETREGSET): Remove.
(get_regset) [ARM || I386]: Remove.
(get_regs) [ARM || I386]: Use PTRACE_GETREGS unconditionally.
1 file changed