add missing argument to usage message.

Fixes #912.

R=rsc
CC=golang-dev
https://golang.org/cl/1819041

diff --git a/src/cmd/gc/lex.c b/src/cmd/gc/lex.c
index 452acfc7607089e437711c76a03b6a59e3a6c06d..7b93001626809ae5448162c7acd339cc2c78582a 100644 (file)
--- a/src/cmd/gc/lex.c
+++ b/src/cmd/gc/lex.c
@@ -35,7 +35,7 @@ enum
 void
 usage(void)
 {
-       print("usage: %cg [flags] file.go...\n");
+       print("gc: usage: %cg [flags] file.go...\n", thechar);
        print("flags:\n");
        // -A is allow use of "any" type, for bootstrapping
        print("  -I DIR search for packages in DIR\n");