powerpc/kprobes: Blacklist emulate_update_regs() from kprobes

Commit 3cdfcbfd ("powerpc: Change analyse_instr so it doesn't
modify *regs") introduced emulate_update_regs() to perform part of what
emulate_step() was doing earlier. However, this function was not added
to the kprobes blacklist. Add it so as to prevent it from being probed.
Signed-off-by: NNaveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Acked-by: NMasami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

arch/powerpc/lib/sstep.c

@@ -2717,6 +2717,7 @@ void emulate_update_regs(struct pt_regs *regs, struct instruction_op *op)
 	}
 	regs->nip = next_pc;
 }
+NOKPROBE_SYMBOL(emulate_update_regs);
 
 /*
  * Emulate a previously-analysed load or store instruction.