[PATCH v2] expand-on-first-boot: Resolve errors in helper script

[Jan Kiszka <jan.kiszka@siemens.com>]

From: Jan Kiszka <jan.kiszka@siemens.com>

Missing quotes broke the -n test, and as we are at it, also resolve the
shellcheck warnings and consolidate over 'find' for retrieving
ROOT_DEV_SLAVE.

Fixes: 15214487e19e ("expand-on-first-boot: Add support for devicemapper")
Reported-by: Felix Moessbauer <felix.moessbauer@siemens.com>
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
---
 .../expand-on-first-boot/files/expand-last-partition.sh       | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/meta/recipes-support/expand-on-first-boot/files/expand-last-partition.sh b/meta/recipes-support/expand-on-first-boot/files/expand-last-partition.sh
index bb371e9f..f3e29a1c 100755
--- a/meta/recipes-support/expand-on-first-boot/files/expand-last-partition.sh
+++ b/meta/recipes-support/expand-on-first-boot/files/expand-last-partition.sh
@@ -11,8 +11,8 @@ set -e
 
 ROOT_DEV="$(findmnt / -o source -n)"
 ROOT_DEV_NAME=${ROOT_DEV##*/}
-ROOT_DEV_SLAVE=$(ls -d /sys/block/${ROOT_DEV_NAME}/slaves/* 2>/dev/null | head -1)
-if [ -n ${ROOT_DEV_SLAVE} ]; then
+ROOT_DEV_SLAVE=$(find /sys/block/"${ROOT_DEV_NAME}"/slaves -mindepth 1 -print -quit 2>/dev/null)
+if [ -n "${ROOT_DEV_SLAVE}" ]; then
 	ROOT_DEV=/dev/${ROOT_DEV_SLAVE##*/}
 fi
 
-- 
2.35.3