cpu: Don't clear cpu->exit_request on reset

cpu->exit_request is part of the execution environment and should
not be cleared when a CPU resets.

Otherwise, we might deadlock QEMU if a CPU resets while there is
I/O going on.
Signed-off-by: NEdgar E. Iglesias <edgar.iglesias@xilinx.com>
Reviewed-by: NPeter Maydell <peter.maydell@linaro.org>
Signed-off-by: NAndreas Färber <afaerber@suse.de>

qom/cpu.c

@@ -195,7 +195,6 @@ static void cpu_common_reset(CPUState *cpu)
         log_cpu_state(cpu, cc->reset_dump_flags);
     }
 
-    cpu->exit_request = 0;
     cpu->interrupt_request = 0;
     cpu->current_tb = NULL;
     cpu->halted = 0;