shell: tweak --help

Even though formally it is -s [ARGS], "sh -s" without ARGS
is the same as just "sh". And we are already over 80 chars wide
for ash --help, so make it shorter.

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
diff --git a/shell/hush.c b/shell/hush.c
index 3a17f5b..6a27b16 100644
--- a/shell/hush.c
+++ b/shell/hush.c
@@ -339,7 +339,7 @@
  * therefore we don't show them either.
  */
 //usage:#define hush_trivial_usage
-//usage:	"[-enxl] [-c 'SCRIPT' [ARG0 ARGS] | FILE [ARGS] | -s [ARGS]]"
+//usage:	"[-enxl] [-c 'SCRIPT' [ARG0 ARGS] | FILE ARGS | -s ARGS]"
 //usage:#define hush_full_usage "\n\n"
 //usage:	"Unix shell interpreter"