Simplify ehdd mount/umount code

ehdd/ehdd_funcs.sh

@@ -24,3 +24,18 @@ keyfile_option() {
         echo "--key-file $EHDD_KEYFILE"
     fi
 }
+
+hdd_exists() {
+    [ -e "$EHDD_IMG" ] && return 0
+    return 1
+}
+
+is_mounted() {
+    [ ! -e "$EHDD_IMG" ] && return 1
+    if mount | grep "^/dev/mapper/$EHDD_LUKS_NAME on $EHDD_MOUNTPOINT" >/dev/null; then
+        # mounted
+        return 0
+    else
+        return 1
+    fi
+}

ehdd/mount.sh

@@ -7,7 +7,7 @@ if [ ! -e "$EHDD_IMG" ]; then
     exit 0
 fi
 
-if mount | grep "^/dev/mapper/$EHDD_LUKS_NAME on $EHDD_MOUNTPOINT" >/dev/null; then
+if is_mounted; then
     echo "$EHDD_IMG already mounted"
     exit 0
 fi

ehdd/umount.sh

@@ -2,7 +2,8 @@
 
 . "ehdd/ehdd_funcs.sh" || exit 1
 
-if ! mount | grep "$EHDD_MOUNTPOINT" >/dev/null; then
+
+if ! is_mounted; then
     # not mounted
     exit 0
 fi