fallback if findmnt is absent

CHANGELOG.md

@@ -5,6 +5,8 @@ and this project **does not adhere to [Semantic Versioning](http://semver.org/sp
 
 ### Added
 
+* fallback if findmnt is absent
+
 ### Changed
 
 ### Deprecated

evomaintenance.sh

@@ -178,9 +178,11 @@ is_repository_readonly() {
     if [ "$(get_system)" = "OpenBSD" ]; then
         partition=$(stat -f '%Sd' $1)
         mount | grep ${partition} | grep -q "read-only"
-    else
+    elif command -v findmnt >/dev/null; then
         mountpoint=$(stat -c '%m' $1)
         findmnt ${mountpoint} --noheadings --output OPTIONS -O ro
+    else
+        grep /usr /proc/mounts | grep -E '\bro\b'
     fi
 }
 remount_repository_readwrite() {