redis

Signed-off-by: Glauber Costa <glommer@cloudius-systems.com>
No need to patch the redis Makefile - just pass LDFLAGS=-shared.

Signed-off-by: Nadav Har'El <nyh@cloudius-systems.com>
"make image=redis" didn't work if "cd apps/redis; make module" wasn't
done earlier - something in the environment bothered redis's make.
Work around it by clearing the environment.

Signed-off-by: Nadav Har'El <nyh@cloudius-systems.com>