Show endpoint direction based on EPHandle bit

Interpret the meaning of the endpoint handle direction bit,
instead of just saying if it is set.

Change-Id: I9fc0d6f95f6c3a94d6db90c8394fe3ca8fc83715
Reviewed-on: https://code.wireshark.org/review/4119
Reviewed-by: Evan Huus <eapache@gmail.com>

epan/dissectors/packet-mausb.c

@@ -1489,7 +1489,7 @@ proto_register_mausb(void)
         /* EP Handle Subfields */
         { &hf_mausb_ep_handle_d,
             { "Direction", "mausb.ep_handle.d", FT_BOOLEAN, 16,
-              TFS(&tfs_set_notset), MAUSB_EP_HANDLE_D, NULL, HFILL
+              TFS(&tfs_endpoint_direction), MAUSB_EP_HANDLE_D, NULL, HFILL
             }
         },
         { &hf_mausb_ep_handle_ep_num,

epan/dissectors/packet-usb.c

@@ -1749,7 +1749,7 @@ dissect_usb_interface_descriptor(packet_info *pinfo, proto_tree *parent_tree,
 }
 
 /* 9.6.6 */
-static const true_false_string tfs_endpoint_direction = {
+const true_false_string tfs_endpoint_direction = {
     "IN Endpoint",
     "OUT Endpoint"
 };

epan/dissectors/packet-usb.h

@@ -198,6 +198,9 @@ typedef struct _usb_tap_data_t {
 #define ENDPOINT_TYPE_BULK              2
 #define ENDPOINT_TYPE_INTERRUPT         3
 
+/* 9.6.6 */
+extern const true_false_string tfs_endpoint_direction;
+
 usb_conv_info_t *
 get_usb_conv_info(conversation_t *conversation);