Update blkid to 2.25.0
Break libblkid into 4 libraries: libblkid, libuuid, libutil-linux and libfdisk.

This should help in later patch updates.

Change-Id: I680d9a7feb031e5c29a603e9c58aff4b65826262
diff --git a/libblkid/libuuid/src/isnull.c b/libblkid/libuuid/src/isnull.c
new file mode 100644
index 0000000..931e7e7
--- /dev/null
+++ b/libblkid/libuuid/src/isnull.c
@@ -0,0 +1,48 @@
+/*
+ * isnull.c --- Check whether or not the UUID is null
+ *
+ * Copyright (C) 1996, 1997 Theodore Ts'o.
+ *
+ * %Begin-Header%
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, and the entire permission notice in its entirety,
+ *    including the disclaimer of warranties.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. The name of the author may not be used to endorse or promote
+ *    products derived from this software without specific prior
+ *    written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE, ALL OF
+ * WHICH ARE HEREBY DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
+ * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
+ * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+ * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE
+ * USE OF THIS SOFTWARE, EVEN IF NOT ADVISED OF THE POSSIBILITY OF SUCH
+ * DAMAGE.
+ * %End-Header%
+ */
+
+#include "uuidP.h"
+
+/* Returns 1 if the uuid is the NULL uuid */
+int uuid_is_null(const uuid_t uu)
+{
+	const unsigned char 	*cp;
+	int			i;
+
+	for (i=0, cp = uu; i < 16; i++)
+		if (*cp++)
+			return 0;
+	return 1;
+}
+