[openwrt/openwrt] base-files: upgrade: Fix export_partdevice() quoting

[LEDE Commits]

hauke pushed a commit to openwrt/openwrt.git, branch master:
https://git.openwrt.org/3cd882744d8ee347e7b55f113a95f93cfe7175cd

commit 3cd882744d8ee347e7b55f113a95f93cfe7175cd
Author: Brian Norris <computersforpeace at gmail.com>
AuthorDate: Tue Dec 20 22:21:46 2022 -0800

    base-files: upgrade: Fix export_partdevice() quoting
    
    $BOOTDEV_MAJOR may be empty for many of the uevents parsed in this
    function. This condition thus tends to fail benignly (we just skip to
    the next device), but it can really clutter the stage2 sysupgrade
    stderr, since it looks like the "=" operand doesn't have an appropriate
    left-hand argument.
    
    Signed-off-by: Brian Norris <computersforpeace at gmail.com>
---
 package/base-files/files/lib/upgrade/common.sh | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/package/base-files/files/lib/upgrade/common.sh b/package/base-files/files/lib/upgrade/common.sh
index 53b8865a57..af1182cb16 100644
--- a/package/base-files/files/lib/upgrade/common.sh
+++ b/package/base-files/files/lib/upgrade/common.sh
@@ -232,7 +232,7 @@ export_partdevice() {
 		while read line; do
 			export -n "$line"
 		done < "$uevent"
-		if [ $BOOTDEV_MAJOR = $MAJOR -a $(($BOOTDEV_MINOR + $offset)) = $MINOR -a -b "/dev/$DEVNAME" ]; then
+		if [ "$BOOTDEV_MAJOR" = "$MAJOR" -a $(($BOOTDEV_MINOR + $offset)) = "$MINOR" -a -b "/dev/$DEVNAME" ]; then
 			export "$var=$DEVNAME"
 			return 0
 		fi