tree-wide: Bump libglnx, port to new lockfile init

In particular I'd like to get the copy fix in, since it might affect users for
the keyring bits.

Update submodule: libglnx

Closes: #1225
Approved by: jlebon

src/libostree/ostree-sysroot.c

@@ -197,7 +197,6 @@ ostree_sysroot_init (OstreeSysroot *self)
                                             keys, G_N_ELEMENTS (keys));
 
   self->sysroot_fd = -1;
-  self->lock = (GLnxLockFile)GLNX_LOCK_FILE_INIT;
 }
 
 /**