Update the code to better reflect recommended style:

Use != instead of <> since <> is documented as "obsolescent".
Use "is" and "is not" when comparing with None or type objects.
diff --git a/Lib/linecache.py b/Lib/linecache.py
index bca40b2..c39f8db 100644
--- a/Lib/linecache.py
+++ b/Lib/linecache.py
@@ -50,7 +50,7 @@
         except os.error:
             del cache[filename]
             continue
-        if size <> stat[ST_SIZE] or mtime <> stat[ST_MTIME]:
+        if size != stat[ST_SIZE] or mtime != stat[ST_MTIME]:
             del cache[filename]