[AX25]: Use kmemdup

Code diff stats:

[acme@newtoy net-2.6.20]$ codiff /tmp/ax25.ko.before /tmp/ax25.ko.after
/pub/scm/linux/kernel/git/acme/net-2.6.20/net/ax25/ax25_out.c:
  ax25_send_frame |   -8
 1 function changed, 8 bytes removed

/pub/scm/linux/kernel/git/acme/net-2.6.20/net/ax25/ax25_route.c:
  ax25_rt_autobind |  -15
 1 function changed, 15 bytes removed

/pub/scm/linux/kernel/git/acme/net-2.6.20/net/ax25/af_ax25.c:
  ax25_make_new |  -33
 1 function changed, 33 bytes removed

/pub/scm/linux/kernel/git/acme/net-2.6.20/net/ax25/sysctl_net_ax25.c:
  ax25_register_sysctl |  -21
 1 function changed, 21 bytes removed

/tmp/ax25.ko.after:
 4 functions changed, 77 bytes removed
[acme@newtoy net-2.6.20]$

Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
diff --git a/net/ax25/ax25_route.c b/net/ax25/ax25_route.c
index 51b7bda..8580356 100644
--- a/net/ax25/ax25_route.c
+++ b/net/ax25/ax25_route.c
@@ -432,11 +432,12 @@
 	}
 
 	if (ax25_rt->digipeat != NULL) {
-		if ((ax25->digipeat = kmalloc(sizeof(ax25_digi), GFP_ATOMIC)) == NULL) {
+		ax25->digipeat = kmemdup(ax25_rt->digipeat, sizeof(ax25_digi),
+					 GFP_ATOMIC);
+		if (ax25->digipeat == NULL) {
 			err = -ENOMEM;
 			goto put;
 		}
-		memcpy(ax25->digipeat, ax25_rt->digipeat, sizeof(ax25_digi));
 		ax25_adjust_path(addr, ax25->digipeat);
 	}