tests: Convert remaining "sys.exit()" to "raise SystemExit".

tests/misc/sys_exc_info.py

@@ -3,7 +3,7 @@ try:
     sys.exc_info
 except:
     print("SKIP")
-    sys.exit()
+    raise SystemExit
 
 def f():
     print(sys.exc_info()[0:2])