Make git-sh-setup-script do what it was supposed to do

Duh. A missing && meant that half the tests that git-sh-setup-script were
_meant_ to do were actually totally ignored.

In particular, the git sanity checking ended up only testing that the 
GIT_OBJECT_DIRECTORY was sane, not that GIT_DIR itself was..

Signed-off-by: Linus Torvalds <torvalds@osdl.org>
---

diff --git a/git-sh-setup-script b/git-sh-setup-script
--- a/git-sh-setup-script
+++ b/git-sh-setup-script

@@ -12,6 +12,6 @@ die() {
 }
 
 [ -d "$GIT_DIR" ] &&
-[ -d "$GIT_DIR/refs" ]
+[ -d "$GIT_DIR/refs" ] &&
 [ -d "$GIT_OBJECT_DIRECTORY" ] &&
 [ -d "$GIT_OBJECT_DIRECTORY/00" ]