ash: [SHELL] Expand ENV before using it

Upstream commit:

    Date: Sun, 13 Jul 2008 21:51:52 +0800
    [SHELL] Expand ENV before using it

    Per POSIX ENV needs to undergo parameter expansion.

    Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

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

shell/hush.c

@@ -8405,6 +8405,7 @@ int hush_main(int argc, char **argv)
 		 * "bash <script>" (which is never interactive (unless -i?))
 		 * sources $BASH_ENV here (without scanning $PATH).
 		 * If called as sh, does the same but with $ENV.
+		 * Also NB, per POSIX, $ENV should undergo parameter expansion.
 		 */
 		G.global_argc--;
 		G.global_argv++;