Compare mount output using base of dirname

If you're building from a bind-mounted directory, the build will
fail as it will find two entries to unmount, but a single unmount
will remove them both causing an error. Adding a space means that
the mountpoint will only match with a single mount entry ; the
expected path, rather than the pre bind-mount.

export-image/05-finalise/01-run.sh

@@ -83,7 +83,7 @@ cp "$ROOTFS_DIR/etc/rpi-issue" "$INFO_FILE"
 	dpkg -l --root "$ROOTFS_DIR"
 } >> "$INFO_FILE"
 
-ROOT_DEV="$(mount | grep "${ROOTFS_DIR} " | cut -f1 -d' ')"
+ROOT_DEV="$(mount | grep " ${ROOTFS_DIR} " | cut -f1 -d' ')"
 
 unmount "${ROOTFS_DIR}"
 zerofree "${ROOT_DEV}"

scripts/common

@@ -47,7 +47,7 @@ unmount(){
 
 	while mount | grep -q "$DIR"; do
 		local LOCS
-		LOCS=$(mount | grep "$DIR" | cut -f 3 -d ' ' | sort -r)
+		LOCS=$(mount | grep " $DIR" | cut -f 3 -d ' ' | sort -r)
 		for loc in $LOCS; do
 			umount "$loc"
 		done