net: remove k{un}map_skb_frag()

Since commit 3e4d3af501 (mm: stack based kmap_atomic()) we dont have
to disable BH anymore while mapping skb frags.

We can remove kmap_skb_frag() / kunmap_skb_frag() helpers and use
kmap_atomic() / kunmap_atomic()

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/appletalk/ddp.c

@@ -63,7 +63,7 @@
 #include <net/tcp_states.h>
 #include <net/route.h>
 #include <linux/atalk.h>
-#include "../core/kmap_skb.h"
+#include <linux/highmem.h>
 
 struct datalink_proto *ddp_dl, *aarp_dl;
 static const struct proto_ops atalk_dgram_ops;
@@ -960,10 +960,10 @@ static unsigned long atalk_sum_skb(const struct sk_buff *skb, int offset,
 
 			if (copy > len)
 				copy = len;
-			vaddr = kmap_skb_frag(frag);
+			vaddr = kmap_atomic(skb_frag_page(frag));
 			sum = atalk_sum_partial(vaddr + frag->page_offset +
 						  offset - start, copy, sum);
-			kunmap_skb_frag(vaddr);
+			kunmap_atomic(vaddr);
 
 			if (!(len -= copy))
 				return sum;