Update launch-in-tmux to avoid some error messages

If tmux wasn't already running it would output an error but still work.
The new approach will suppress that since we're not concerned if it's
already running or not, just whether the desired session is.

Modified the live macOS args to support connecting to the HW-Diags
session remotely (more easily at least).

scripts/launch-in-tmux

@@ -5,7 +5,7 @@
 # Live macOS env workaround
 tmux_args=()
 if [[ -e "/.wk-live-macos" ]]; then
-  tmux_args=(-f "/etc/tmux.conf" -S "$(mktemp).socket")
+  tmux_args=(-f "/etc/tmux.conf" -S "/Volumes/RAM_Disk/.tmux.socket")
 fi
 
 function ask() {
@@ -31,7 +31,7 @@ function launch_in_tmux() {
   [[ -n "${TMUX_CMD:-}" ]] || return $(err "Required variable missing (TMUX_CMD)")
 
   # Check for running session
-  if tmux "${tmux_args[@]}" list-session | grep -q "$SESSION_NAME"; then
+  if tmux "${tmux_args[@]}" list-session 2>&1 | grep -q "$SESSION_NAME"; then
     echo "WARNING: tmux session $SESSION_NAME already exists."
     echo ""
     if ask "Connect to current session?"; then