ibm_emac: Convert to use napi_struct independent of struct net_device

Commit da3dedd9 ("[NET]: Make NAPI polling independent of struct
net_device objects.") changed the interface to NAPI polling.  Fix up
the ibm_emac driver so that it works with this new interface.  This is
actually a nice cleanup because ibm_emac is one of the drivers that
wants to have multiple NAPI structures for a single net_device.

Tested with the internal MAC of a PowerPC 440SPe SoC with an AMCC
'Yucca' evaluation board.

Signed-off-by: Roland Dreier <rolandd@cisco.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index 91cd3f3..4848c7a 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -349,6 +349,16 @@
 		__napi_schedule(n);
 }
 
+/* Try to reschedule poll. Called by dev->poll() after napi_complete().  */
+static inline int napi_reschedule(struct napi_struct *napi)
+{
+	if (napi_schedule_prep(napi)) {
+		__napi_schedule(napi);
+		return 1;
+	}
+	return 0;
+}
+
 /**
  *	napi_complete - NAPI processing complete
  *	@n: napi context