Fix MCT data transport for the BT HAL

The vendor open interface command returns the total number
of FDs opened. (2 or 4 if the interface is MCT)

However, the list of FDs is always 4 in either case. If the
open command returns 2, the FDs are shared cmd/event and
data in/out.

2 FDs example
[41, 41, 42, 42]

4 FDs example
[41, 42, 43, 44]

If we condition the registration of ACL_IN on the total
number of FDs, then 2 FD MCT interfaces will not get data.

Fixes: 36067612, 36035039, 36188793
Test: manual, pairing is quick and data does transfer
Change-Id: Icc8728239ba81426d5fc0e678c5c5480fd9b5081
diff --git a/bluetooth/1.0/default/vendor_interface.cc b/bluetooth/1.0/default/vendor_interface.cc
index 26f52f7..e6575b0 100644
--- a/bluetooth/1.0/default/vendor_interface.cc
+++ b/bluetooth/1.0/default/vendor_interface.cc
@@ -248,10 +248,9 @@
         new hci::MctProtocol(fd_list, intercept_events, acl_cb);
     fd_watcher_.WatchFdForNonBlockingReads(
         fd_list[CH_EVT], [mct_hci](int fd) { mct_hci->OnEventDataReady(fd); });
-    if (fd_count >= CH_ACL_IN)
-      fd_watcher_.WatchFdForNonBlockingReads(
-          fd_list[CH_ACL_IN],
-          [mct_hci](int fd) { mct_hci->OnAclDataReady(fd); });
+    fd_watcher_.WatchFdForNonBlockingReads(
+        fd_list[CH_ACL_IN],
+        [mct_hci](int fd) { mct_hci->OnAclDataReady(fd); });
     hci_ = mct_hci;
   }