bc: do not show -i in --help, it's a NOP (for now)

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
diff --git a/miscutils/bc.c b/miscutils/bc.c
index 7ecddf0..0b891d8 100644
--- a/miscutils/bc.c
+++ b/miscutils/bc.c
@@ -110,7 +110,7 @@
 
 //See www.gnu.org/software/bc/manual/bc.html
 //usage:#define bc_trivial_usage
-//usage:       "[-sqliw] FILE..."
+//usage:       "[-sqlw] FILE..."
 //usage:
 //usage:#define bc_full_usage "\n"
 //usage:     "\nArbitrary precision calculator"