Portable trap conditions in run-test.sh.

Posix says:
    The condition can be EXIT, 0 (equivalent to EXIT), or a signal
    specified using a symbolic name, without the SIG prefix, as listed
    in the tables of signal names in the <signal.h> header defined in
    the Base Definitions volume of IEEE Std 1003.1-2001, Chapter 13,
    Headers; for example, HUP, INT, QUIT, TERM. Implementations may
    permit names with the SIG prefix or ignore case in signal names as
    an extension.

Remove 'SIG' from trap conditions in run-test.sh for portability.
diff --git a/test/run-test.sh b/test/run-test.sh
index a46e9a7..34d9fc0 100644
--- a/test/run-test.sh
+++ b/test/run-test.sh
@@ -48,13 +48,13 @@
 
 clean_exit() {
     rc=$?
-    trap - SIGINT SIGTERM SIGABRT EXIT
+    trap - INT TERM ABRT EXIT
     if [ "x$TEST" != "x" ]; then
         echo "Aborting from '$TEST' with the exit code $rc"
     fi
     exit $rc
 }
-trap clean_exit SIGINT SIGTERM SIGABRT EXIT
+trap clean_exit INT TERM ABRT EXIT
 
 check () {
     {