fsck: re-enable fsck -l

The -l (lock) has been temporary disabled due to conflict with
udev (https://bugs.freedesktop.org/show_bug.cgi?id=79576)

The problem is fixed since util-linux v2.25 (Jul 2014).

README

@@ -129,8 +129,9 @@ REQUIREMENTS:
         During runtime, you need the following additional
         dependencies:
 
-        util-linux >= v2.19 (requires fsck -l, agetty -s),
+        util-linux >= v2.19 required for agetty -s
                       v2.21 required for tests in test/
+                      v2.25 required for fsck -l
         dbus >= 1.4.0 (strictly speaking optional, but recommended)
         sulogin (from util-linux >= 2.22 or sysvinit-tools, optional but recommended,
                  required for tests in test/)

src/fsck/fsck.c

@@ -320,16 +320,11 @@ int main(int argc, char *argv[]) {
         cmdline[i++] = "-T";
 
         /*
-         * Disable locking which conflict with udev's event
-         * ownershipi, until util-linux moves the flock
-         * synchronization file which prevents multiple fsck running
-         * on the same rotationg media, from the disk device
-         * node to a privately owned regular file.
-         *
-         * https://bugs.freedesktop.org/show_bug.cgi?id=79576#c5
-         *
-         * cmdline[i++] = "-l";
+         * Since util-linux v2.25 fsck uses /run/fsck/<diskname>.lock files.
+         * The previous versions use flock for the device and conflict with
+         * udevd, see https://bugs.freedesktop.org/show_bug.cgi?id=79576#c5
          */
+        cmdline[i++] = "-l";
 
         if (!root_directory)
                 cmdline[i++] = "-M";