HID: simplify an index check in hid_lookup_collection

Save the struct hid_collection * in a temporary to shorten
the generated code a bit and perhaps improve readability.

$ size drivers/hid/hid-core.o*
   text	   data	    bss	    dec	    hex	filename
  16460	     78	      8	  16546	   40a2	drivers/hid/hid-core.o.new
  16469	     78	      8	  16555	   40ab	drivers/hid/hid-core.o.old
Signed-off-by: NJoe Perches <joe@perches.com>
Signed-off-by: NJiri Kosina <jkosina@suse.cz>

drivers/hid/hid-core.c

@@ -178,10 +178,14 @@ static int close_collection(struct hid_parser *parser)
 
 static unsigned hid_lookup_collection(struct hid_parser *parser, unsigned type)
 {
+	struct hid_collection *collection = parser->device->collection;
 	int n;
-	for (n = parser->collection_stack_ptr - 1; n >= 0; n--)
-		if (parser->device->collection[parser->collection_stack[n]].type == type)
-			return parser->device->collection[parser->collection_stack[n]].usage;
+
+	for (n = parser->collection_stack_ptr - 1; n >= 0; n--) {
+		unsigned index = parser->collection_stack[n];
+		if (collection[index].type == type)
+			return collection[index].usage;
+	}
 	return 0; /* we know nothing about this usage type */
 }