diff: pacify compiler re style

* src/diff.c (usage): Prefer &"string"[N] to "string" + N.
Some compilers complain about the latter, as they worry C++
refugees will think it’s string concatnation.

1 files changed, 1 insertions, 1 deletions

diff --git a/src/diff.c b/src/diff.c
index 3871715..6af50e8 100644
--- a/src/diff.c
+++ b/src/diff.c
@@ -1018,7 +1018,7 @@ Mandatory arguments to long options are mandatory for short options too.\n\
               msg = nl + 1;
             }
 
-          printf ("  %s\n" + 2 * (*msg != ' ' && *msg != '-'), msg);
+          printf (&"  %s\n"[2 * (*msg != ' ' && *msg != '-')], msg);
         }
     }
   emit_bug_reporting_address ();