xprtrdma: Clean up of xprtrdma chunk trace points

The chunk-related trace points capture nearly the same information
as the MR-related trace points.

Also, rename them so globbing can be used to enable or disable
these trace points more easily.

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