db/fixup_kernel.sh: fix clear_user() handling
There are two changes here:
1) Switch from double quotes to single quotes. Atin Bainada reported that
this was still an issue.
2) Add a grep -v '\['. Apparently current versions of smatch are able to
determine some of these relationship automatically and this code was
recording bogus relationships like: "1-u64max[==$1][<=$1]" when it
should have just been "1-u64max[==$1]".
Reported-by: Atin Bainada
Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>