remove dependency on <linux/input.h>

* and kill a warning

djvu.c

@@ -44,7 +44,7 @@ static int handle(lua_State *L, ddjvu_context_t *ctx, int wait)
 {
 	const ddjvu_message_t *msg;
 	if (!ctx)
-		return;
+		return -1;
 	if (wait)
 		msg = ddjvu_message_wait(ctx);
 	while ((msg = ddjvu_message_peek(ctx)))

input.c

@@ -20,7 +20,12 @@
 #include <errno.h>
 #include <unistd.h>
 #include <stdlib.h>
+#ifdef EMULATE_READER
+#include <SDL.h>
+#define EV_KEY 0x01
+#else
 #include <linux/input.h>
+#endif
 #include "input.h"
 #include <sys/types.h>
 #include <sys/wait.h>
@@ -138,6 +143,7 @@ static int openInputDevice(lua_State *L) {
 }
 
 static int closeInputDevices(lua_State *L) {
+#ifndef EMULATE_READER
 	int i;
 	for(i=0; i<NUM_FDS; i++) {
 		if(inputfds[i] != -1) {
@@ -151,6 +157,9 @@ static int closeInputDevices(lua_State *L) {
 		waitpid(-1, NULL, 0);
 	}
 	return 0;
+#else
+	return 0;
+#endif
 }
 
 static int waitForInput(lua_State *L) {

input.h

@@ -18,10 +18,6 @@
 #ifndef _PDF_INPUT_H
 #define _PDF_INPUT_H
 
-#ifdef EMULATE_READER
-#include <SDL.h>
-#endif
-
 #include <lua.h>
 #include <lualib.h>
 #include <lauxlib.h>