diff: avoid duplicate definition of presume_output_tty

* src/util.c (presume_output_tty): Remove this definition.
The other is in diff.h.  Reported in https://bugs.gnu.org/24248

1 files changed, 0 insertions, 2 deletions

diff --git a/src/util.c b/src/util.c
index d7b8925..76872cb 100644
--- a/src/util.c
+++ b/src/util.c
@@ -44,8 +44,6 @@
 
 char const pr_program[] = PR_PROGRAM;
 
-bool presume_output_tty;
-
 /* Queue up one-line messages to be printed at the end,
    when -l is specified.  Each message is recorded with a 'struct msg'.  */