maint: avoid -Werror=strict-overflow warnings with GCC 5

All warnings were of the form: "assuming signed overflow does not occur
when simplifying conditional to constant [-Werror=strict-overflow]"

* src/dd.c (cache_round): Use an appropriately sized unsigned type,
to avoid possibility of undefined signed overflow.
* src/mknod.c (main): Likewise.
* src/pr.c (pad_down): Likewise.
* src/wc.c (main): Likewise.
* src/tail.c (main): Assert that argc >= 0 thus allowing the
compiler to assume without implication that argc - optind
is positive.

1 files changed, 1 insertions, 1 deletions

diff --git a/src/mknod.c b/src/mknod.c
index 2804aaf7c..73342ce29 100644
--- a/src/mknod.c
+++ b/src/mknod.c
@@ -94,7 +94,7 @@ main (int argc, char **argv)
   mode_t newmode;
   char const *specified_mode = NULL;
   int optc;
-  int expected_operands;
+  size_t expected_operands;
   mode_t node_type;
   char const *scontext = NULL;
   bool set_security_context = false;