SUNRPC: Refresh the show_rqstp_flags() macro

Ensure that show_rqstp_flags() can recognize and display the
RQ_AUTHERR flag, added in commit 83dd59a0 ("SUNRPC/nfs: Fix
return value for nfs4_callback_compound()") and the RQ_DATA flag,
added in commit ff3ac5c3 ("SUNRPC: Add a server side
per-connection limit").

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>