net: Fix wrong interpretation of some copy_to_user() results.

I found some places, that erroneously return the value obtained from
the copy_to_user() call: if some amount of bytes were not able to get
to the user (this is what this one returns) the proper behavior is to
return the -EFAULT error, not that number itself.

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/can/raw.c b/net/can/raw.c
index ead50c7..201cbfc 100644
--- a/net/can/raw.c
+++ b/net/can/raw.c
@@ -573,7 +573,8 @@
 			int fsize = ro->count * sizeof(struct can_filter);
 			if (len > fsize)
 				len = fsize;
-			err = copy_to_user(optval, ro->filter, len);
+			if (copy_to_user(optval, ro->filter, len))
+				err = -EFAULT;
 		} else
 			len = 0;
 		release_sock(sk);