Use imperative form in help usage to describe an action

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
diff --git a/builtin/push.c b/builtin/push.c
index 4840bc2..8686a7a 100644
--- a/builtin/push.c
+++ b/builtin/push.c
@@ -364,7 +364,7 @@
 		OPT_BIT( 0,  "porcelain", &flags, N_("machine-readable output"), TRANSPORT_PUSH_PORCELAIN),
 		OPT_BIT('f', "force", &flags, N_("force updates"), TRANSPORT_PUSH_FORCE),
 		{ OPTION_CALLBACK, 0, "recurse-submodules", &flags, N_("check"),
-			N_("controls recursive pushing of submodules"),
+			N_("control recursive pushing of submodules"),
 			PARSE_OPT_OPTARG, option_parse_recurse_submodules },
 		OPT_BOOLEAN( 0 , "thin", &thin, N_("use thin pack")),
 		OPT_STRING( 0 , "receive-pack", &receivepack, "receive-pack", N_("receive pack program")),