[3.0.x] Fixed typo in BulkInsertMapper constant name.

Backport of 67e7dffe95 from master

django/db/backends/oracle/utils.py

@@ -51,7 +51,7 @@ class Oracle_datetime(datetime.datetime):
 
 class BulkInsertMapper:
     BLOB = 'TO_BLOB(%s)'
-    CBLOB = 'TO_CLOB(%s)'
+    CLOB = 'TO_CLOB(%s)'
     DATE = 'TO_DATE(%s)'
     INTERVAL = 'CAST(%s as INTERVAL DAY(9) TO SECOND(6))'
     NUMBER = 'TO_NUMBER(%s)'
@@ -71,6 +71,6 @@ class BulkInsertMapper:
         'PositiveIntegerField': NUMBER,
         'PositiveSmallIntegerField': NUMBER,
         'SmallIntegerField': NUMBER,
-        'TextField': CBLOB,
+        'TextField': CLOB,
         'TimeField': TIMESTAMP,
     }