ieee1394: eth1394: clean up fragment_overlap

offset > fi->offset + fi->len - 1  ==  !(offset < fi->offset + fi->len)
offset + len - 1 < fi->offset      ==  !(offset + len > fi->offset)
!(A || B)  ==  (!A && !B)

Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
diff --git a/drivers/ieee1394/eth1394.c b/drivers/ieee1394/eth1394.c
index 0047343..08f63c8 100644
--- a/drivers/ieee1394/eth1394.c
+++ b/drivers/ieee1394/eth1394.c
@@ -867,12 +867,12 @@
 static int fragment_overlap(struct list_head *frag_list, int offset, int len)
 {
 	struct fragment_info *fi;
+	int end = offset + len;
 
-	list_for_each_entry(fi, frag_list, list) {
-		if ( ! ((offset > (fi->offset + fi->len - 1)) ||
-		       ((offset + len - 1) < fi->offset)))
+	list_for_each_entry(fi, frag_list, list)
+		if (offset < fi->offset + fi->len && end > fi->offset)
 			return 1;
-	}
+
 	return 0;
 }