Fix notes which differnt from actual parameters

Some notes are not the same as actual parameters, this will cause
confusion.

Change-Id: I25345616e3ca7ab7a55055a6ae01f85ed266b6dd
diff --git a/tempest/lib/common/rest_client.py b/tempest/lib/common/rest_client.py
index 1b0f53a..274ee31 100644
--- a/tempest/lib/common/rest_client.py
+++ b/tempest/lib/common/rest_client.py
@@ -64,7 +64,7 @@
                                                     certificate validation
     :param str ca_certs: File containing the CA Bundle to use in verifying a
                          TLS server cert
-    :param str trace_request: Regex to use for specifying logging the entirety
+    :param str trace_requests: Regex to use for specifying logging the entirety
                               of the request and response payload
     """
     TYPE = "json"