threadsafety: use $# instead of $1

That works around an issue with an "unbound variable" error
in latest automakes. Reported by LRN.

1 files changed, 1 insertions, 1 deletions

diff --git a/tests/threadsafety b/tests/threadsafety
index bfbc86a..608fa16 100755
--- a/tests/threadsafety
+++ b/tests/threadsafety
@@ -162,7 +162,7 @@ UNSAFE="$UNSAFE srandom"
 set -- $UNSAFE
 cmd="-e [^.>=_0-9a-z]($1"
 shift
-while test "$1"; do
+while test $# != 0; do
     cmd="${cmd}|$1"
     shift
 done