sandbox: Tidy up terminal restore

For some reason 'u-boot -D' does not restore the terminal correctly when
the 'reset' command is used. Call the terminal restore function explicitly
in this case.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Joe Hershberger <joe.hershberger@ni.com>
diff --git a/arch/sandbox/cpu/cpu.c b/arch/sandbox/cpu/cpu.c
index b6aae37..02c4cd3 100644
--- a/arch/sandbox/cpu/cpu.c
+++ b/arch/sandbox/cpu/cpu.c
@@ -22,6 +22,8 @@
 
 void reset_cpu(ulong ignored)
 {
+	/* Do this here while it still has an effect */
+	os_fd_restore();
 	if (state_uninit())
 		os_exit(2);
 
diff --git a/arch/sandbox/cpu/os.c b/arch/sandbox/cpu/os.c
index e6dd17e..8a4d719 100644
--- a/arch/sandbox/cpu/os.c
+++ b/arch/sandbox/cpu/os.c
@@ -107,10 +107,12 @@
 static struct termios orig_term;
 static bool term_setup;
 
-static void os_fd_restore(void)
+void os_fd_restore(void)
 {
-	if (term_setup)
+	if (term_setup) {
 		tcsetattr(0, TCSANOW, &orig_term);
+		term_setup = false;
+	}
 }
 
 /* Put tty into raw mode so <tab> and <ctrl+c> work */
@@ -120,7 +122,6 @@
 
 	if (term_setup)
 		return;
-	term_setup = true;
 
 	/* If not a tty, don't complain */
 	if (tcgetattr(fd, &orig_term))
@@ -134,6 +135,7 @@
 	if (tcsetattr(fd, TCSANOW, &term))
 		return;
 
+	term_setup = true;
 	atexit(os_fd_restore);
 }