Switch to correct SPDX license identifier

Switch to LGPL-2.1-or-later according to
https://github.com/storaged-project/libblockdev



Signed-off-by: David Runge <dvzrv@archlinux.org>

PKGBUILD

@@ -6,7 +6,7 @@ pkgrel=4
 pkgdesc="A library for manipulating block devices"
 arch=('x86_64')
 url="https://github.com/storaged-project/libblockdev"
-license=('LGPL')
+license=(LGPL-2.1-or-later)
 depends=('cryptsetup' 'device-mapper' 'e2fsprogs' 'gcc-libs' 'glib2' 'glibc' 'gptfdisk' 'kmod'
          'libbytesize' 'mdadm' 'nss' 'parted' 'systemd-libs' 'util-linux' 'volume_key')
 makedepends=('autoconf-archive' 'gobject-introspection' 'gtk-doc' 'ndctl' 'python')