udev-extraconf: Skip the entry in /etc/fstab when using the systemd-mount

When using systemd, the systemd-fstab-generator would parse the
/etc/fstab and create the corresponding unit dynamically. So we don't
need to handle the ADD action for the partitions in /etc/fstab.

(From OE-Core rev: 6104109ceba1a1323e42d67a632921fb91184ab6)

Signed-off-by: Kevin Hao <kexin.hao@windriver.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

meta/recipes-core/udev/udev-extraconf/mount.sh

@@ -38,6 +38,15 @@ done
 automount_systemd() {
     name="`basename "$DEVNAME"`"
 
+    # Skip the partition which are already in /etc/fstab
+    grep "^[[:space:]]*$DEVNAME" /etc/fstab && return
+    for n in LABEL PARTLABEL UUID PARTUUID; do
+        tmp="$(lsblk -o $n $DEVNAME | sed -e '1d')"
+        test -z "$tmp" && continue
+        tmp="$n=$tmp"
+        grep "^[[:space:]]*$tmp" /etc/fstab && return
+    done
+
     [ -d "/run/media/$name" ] || mkdir -p "/run/media/$name"
 
     MOUNT="$MOUNT -o silent"