usbmon: restore mmap

Paolo asked to enable the mmap. I kept it off because I'm do not
entirely understand how it workse these days after ->nopage etc.
But it seems like working somewhat at least.

Signed-Off-By: Pete Zaitcev <[e-mail]>
Cc: Paolo Abeni <[e-mail]>
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

drivers/usb/mon/mon_bin.c

···
 	return mask;
 }
 
-#if 0
-
 /*
  * open and close: just keep track of how many times the device is
  * mapped, to use the proper memory allocation function.
···
 	return 0;
 }
 
-struct vm_operations_struct mon_bin_vm_ops = {
+static struct vm_operations_struct mon_bin_vm_ops = {
 	.open =     mon_bin_vma_open,
 	.close =    mon_bin_vma_close,
 	.fault =    mon_bin_vma_fault,
 };
 
-int mon_bin_mmap(struct file *filp, struct vm_area_struct *vma)
+static int mon_bin_mmap(struct file *filp, struct vm_area_struct *vma)
 {
 	/* don't do anything here: "fault" will set up page table entries */
 	vma->vm_ops = &mon_bin_vm_ops;
···
 	mon_bin_vma_open(vma);
 	return 0;
 }
-
-#endif  /*  0  */
 
 static const struct file_operations mon_fops_binary = {
 	.owner =	THIS_MODULE,
···
 	.poll =		mon_bin_poll,
 	.ioctl =	mon_bin_ioctl,
 	.release =	mon_bin_release,
+	.mmap =		mon_bin_mmap,
 };
 
 static int mon_bin_wait_event(struct file *file, struct mon_reader_bin *rp)

drivers/usb/mon/mon_main.c

···
 
 /*
  */
-static void mon_bus_complete(struct mon_bus *mbus, struct urb *urb,
-		int status)
+static void mon_bus_complete(struct mon_bus *mbus, struct urb *urb, int status)
 {
 	unsigned long flags;
 	struct list_head *pos;