sparc, sparc64: fix syscall tampering when PTRACE_GET_SYSCALL_INFO is in use

sparc, sparc64: fix syscall tampering when PTRACE_GET_SYSCALL_INFO is in use

When PTRACE_GET_SYSCALL_INFO is in use on sparc, psr is not loaded,
so it has to be loaded explicitly before tampering.
Likewise, when PTRACE_GET_SYSCALL_INFO is in use on sparc64, tstate
is not loaded, so it has to be loaded explicitly before tampering.

* linux/sparc/set_error.c (arch_set_error, arch_set_success): Explicitly
call get_regs before changing psr when PTRACE_GET_SYSCALL_INFO is in use.
* linux/sparc64/set_error.c (arch_set_error, arch_set_success):
Explicitly call get_regs before changing tstate when
PTRACE_GET_SYSCALL_INFO is in use.
* NEWS: Mention this fix.