maint: avoid double semicolon syntax check failure

A syntax-check recently added to gnulib would trigger a failure
(once gnulib gets updated here) for a statement introduced with
commit v8.23-43-gaf2a4ed:

  src/dd.c:806:  char const *time_fmt = _(", %g s, %s/s\n");;
  maint.mk: Double semicolon detected
  make: *** [sc_prohibit_double_semicolon] Error 1

* src/dd.c (print_xfer_stats): s/;;/;/

1 files changed, 1 insertions, 1 deletions

diff --git a/src/dd.c b/src/dd.c
index 40181908d..78433ff58 100644
--- a/src/dd.c
+++ b/src/dd.c
@@ -803,7 +803,7 @@ print_xfer_stats (xtime_t progress_time) {
      but that was incorrect for languages like Polish.  To fix this
      bug we now use SI symbols even though they're a bit more
      confusing in English.  */
-  char const *time_fmt = _(", %g s, %s/s\n");;
+  char const *time_fmt = _(", %g s, %s/s\n");
   if (progress_time)
     time_fmt = _(", %.6f s, %s/s");  /* OK with '\r' as increasing width.  */
   fprintf (stderr, time_fmt, delta_s, bytes_per_second);