run individual spatch form check-cocci.sh

run individual spatch form check-cocci.sh

Add util/check-cocci.sh support for a command-line argument which is a
path to a spatch file. Running `util/check-cocci.sh` runs all the spatch
in `cocci` folder. Running `util/check-cocci.sh cocci/foo.spatch` only
run the spatch `cocci/foo.spatch`.

Any command line parameters after `--` are forwarded to `spatch`
command, for instance:

`util/check-cocci.sh -- --debug`
`util/check-cocci.sh cocci/foo.spatch -- --debug`

Will (1) run all spatch files in cocci/ with --debug spatch option and
(2) run only `cocci/foo.spatch` with --debug options.