hexdump: need to use xstrtoull for off_t

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
diff --git a/util-linux/hexdump.c b/util-linux/hexdump.c
index 43fc188..4d998b9 100644
--- a/util-linux/hexdump.c
+++ b/util-linux/hexdump.c
@@ -116,7 +116,7 @@
 			dumper->dump_length = xatoi_positive(optarg);
 		} /* else */
 		if (ch == 's') { /* compat: -s accepts hex numbers too */
-			dumper->dump_skip = xstrtoul_range_sfx(
+			dumper->dump_skip = xstrtoull_range_sfx(
 				optarg,
 				/*base:*/ 0,
 				/*lo:*/ 0, /*hi:*/ OFF_T_MAX,