squashfs: fix 3.4 build after be8a104c (pass CFLAGS/LDFLAGS and add host-zlib dependency)

Commit be8a104c (pass CFLAGS/LDFLAGS and add host-zlib dependency)
changed the way make was invocated for squashfs and added a patch for 4.0,
but forgot to add an equivalent patch for 3.4.

Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>