more C standard compat fixes from Dan Fandrich

function                                             old     new   delta
docolon                                              207     204      -3

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

shell/msh_unused.c

@@ -2064,7 +2064,7 @@ static int rlookup(char *n)
 		{ "{"    , '{'    },
 		{ "}"    , '}'    },
 		{ "."    , DOT    },
-		{ },
+		{ ""     , 0      },
 	};
 
 	const struct res *rp;