Revert "Send logcat ouput over serial ports instead of vsocket"

This reverts commit f56f6b404e21463b3b68141de46a468ce222e6ba.

Reason for revert: test failures

Change-Id: I9b4c7d17f00e984ca04df7ca3d4b1e4b2dfcfe7d
diff --git a/host/libs/vm_manager/cf_qemu.sh b/host/libs/vm_manager/cf_qemu.sh
index 835c1ed..157f941 100755
--- a/host/libs/vm_manager/cf_qemu.sh
+++ b/host/libs/vm_manager/cf_qemu.sh
@@ -144,10 +144,12 @@
     -device "ivshmem-doorbell,chardev=ivsocket,vectors=${ivshmem_vector_count}"
 )
 
-args+=(
-    -chardev "file,id=charchannel0,path=${logcat_path:-${default_dir}/logcat},append=on"
-    -device "virtserialport,bus=virtio-serial0.0,nr=1,chardev=charchannel0,id=channel0,name=cf-logcat"
-)
+if [[ "${logcat_mode}" == "serial" ]]; then
+    args+=(
+        -chardev "file,id=charchannel0,path=${logcat_path:-${default_dir}/logcat},append=on"
+        -device "virtserialport,bus=virtio-serial0.0,nr=1,chardev=charchannel0,id=channel0,name=cf-logcat"
+    )
+fi
 
 if [[ -n "${gdb_flag}" ]]; then
   args+=(-gdb "${gdb_flag}")