Remove not used code

Signed-off-by: Jianhui Zhao <jianhuizhao329@gmail.com>

src/main.c

@@ -38,7 +38,6 @@ struct tty_session {
 
 enum {
     RTTYD_TYPE,
-    RTTYD_DID,
     RTTYD_SID,
     RTTYD_ERR,
     RTTYD_DATA
@@ -49,10 +48,6 @@ static const struct blobmsg_policy pol[] = {
         .name = "type",
         .type = BLOBMSG_TYPE_STRING,
     },
-    [RTTYD_DID] = {
-        .name = "did",
-        .type = BLOBMSG_TYPE_STRING,
-    },
     [RTTYD_SID] = {
         .name = "sid",
         .type = BLOBMSG_TYPE_STRING,