Emit shell prompt even when in non-interactive mode.

Change-Id: If85c509efe13e4bdb40216c79d560ea7f83ba813
diff --git a/sh/input.h b/sh/input.h
index a9d3a12..99c1b77 100644
--- a/sh/input.h
+++ b/sh/input.h
@@ -46,6 +46,7 @@
 extern char *parsenextc;	/* next character in input buffer */
 extern int init_editline;	/* 0 == not setup, 1 == OK, -1 == failed */
 
+int in_interactive_mode();
 char *pfgets(char *, int);
 int pgetc(void);
 int preadbuffer(void);