usb/redirect.c: unbreak compilation due to include/char/char.h

Broken since:

commit 927d4878
Author: Paolo Bonzini <pbonzini@redhat.com>
Date:   Mon Dec 17 18:20:05 2012 +0100

    softmmu: move remaining include files to include/ subdirectories
Signed-off-by: NAlon Levy <alevy@redhat.com>
Signed-off-by: NBlue Swirl <blauwirbel@gmail.com>

hw/usb/redirect.c

@@ -30,6 +30,7 @@
 #include "monitor/monitor.h"
 #include "sysemu/sysemu.h"
 #include "qemu/iov.h"
+#include "char/char.h"
 
 #include <dirent.h>
 #include <sys/ioctl.h>