torture: Fix remaining erroneous torture.sh instance of $*

Although "eval" was removed from torture.sh, that commit failed to
update the KCSAN instance of $* to "$@".  This results in failures when
(for example) --bootargs is given more than one argument.  This commit
therefore makes this change.

There is one remaining instance of $* in torture.sh, but this
is used only in the "echo" command, where quoting doesn't matter
so much.

Fixes: 197220d4 ("torture: Remove use of "eval" in torture.sh")
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>