stage-1: add datestamps to logs

When the stage-1 logs get imported in to the journal, they all get
loaded with the same timestamp. This makes it difficult to identify
what might be taking a long time in early boot.

nixos/modules/system/boot/stage-1-init.sh

@@ -120,7 +120,7 @@ eval "exec $logOutFd>&1 $logErrFd>&2"
 if test -w /dev/kmsg; then
     tee -i < /tmp/stage-1-init.log.fifo /proc/self/fd/"$logOutFd" | while read -r line; do
         if test -n "$line"; then
-            echo "<7>stage-1-init: $line" > /dev/kmsg
+            echo "<7>stage-1-init: [$(date)] $line" > /dev/kmsg
         fi
     done &
 else