Patch based on kexec-tools, fixes undefined loff_t
--- src/nwipe.h.orig
+++ src/nwipe.h
@@ -38,7 +38,9 @@
 
 /* System headers. */
 #include <errno.h>
+#define _GNU_SOURCE
 #include <fcntl.h>
+#undef _GNU_SOURCE
 #include <getopt.h>
 #include <math.h>
 #include <pthread.h>
