powerpc: Don't use the wrong thread_struct for ptrace get/set VSX regs

In PTRACE_GET/SETVSRREGS, we should be using the thread we are
ptracing rather than current.

Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
1 file changed