fix duplicated grep usage printing

Change-Id: I579d2046f96ba8ae9fd0bf8f36e2e2f64da622ea
Signed-off-by: Rocky Zhang <zhangyan.hit@gmail.com>
diff --git a/toolbox/grep/grep.c b/toolbox/grep/grep.c
index 7b2c487..7dc4bcc 100644
--- a/toolbox/grep/grep.c
+++ b/toolbox/grep/grep.c
@@ -159,7 +159,6 @@
 {
 	fprintf(stderr, getstr(4), __progname);
 	fprintf(stderr, "%s", getstr(5));
-	fprintf(stderr, "%s", getstr(5));
 	fprintf(stderr, "%s", getstr(6));
 	fprintf(stderr, "%s", getstr(7));
 	exit(2);