NFC: Fix next target_idx type and rename for clarity

Signed-off-by: Eric Lapuyade <eric.lapuyade@intel.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/net/nfc/core.c b/net/nfc/core.c
index d924000..db88429 100644
--- a/net/nfc/core.c
+++ b/net/nfc/core.c
@@ -435,7 +435,7 @@
 	dev->polling = false;
 
 	for (i = 0; i < n_targets; i++)
-		targets[i].idx = dev->target_idx++;
+		targets[i].idx = dev->target_next_idx++;
 
 	spin_lock_bh(&dev->targets_lock);