bios_emulator: Don't display error when emulator terminates

As it turns out this is a normal condition, so suppress the error.

Signed-off-by: Simon Glass <sjg@chromium.org>

drivers/bios_emulator/x86emu/ops.c

@@ -179,7 +179,7 @@ void x86emuOp_illegal_op(
 {
     START_OF_INSTR();
     if (M.x86.R_SP != 0) {
-	ERR_PRINTF("ILLEGAL X86 OPCODE\n");
+	DB(printf("ILLEGAL X86 OPCODE\n"));
 	TRACE_REGS();
 	DB( printk("%04x:%04x: %02X ILLEGAL X86 OPCODE!\n",
 	    M.x86.R_CS, M.x86.R_IP-1,op1));