maint: update preferred contributor name

Based on off-list discussion with Royce.

* AUTHORS: Update to Royce Lv's preferred anglicized name.
* .mailmap: Likewise.

.mailmap

@@ -34,4 +34,4 @@
 # Name consolidation:
 # Preferred author spelling <preferred email>
 Alex Jia <ajia@redhat.com>
-Wen Ruo Lv <lvroyce@linux.vnet.ibm.com>
+Royce Lv <lvroyce@linux.vnet.ibm.com>

AUTHORS

@@ -199,7 +199,7 @@ Patches have also been contributed by:
   Sage Weil            <sage@newdream.net>
   David L Stevens      <dlstevens@us.ibm.com>
   Tyler Coumbes        <coumbes@gmail.com>
-  Wen Ruo Lv           <lvroyce@linux.vnet.ibm.com>
+  Royce Lv             <lvroyce@linux.vnet.ibm.com>
   Patrice LACHANCE     <patlachance@gmail.com>
   Eli Qiao             <taget@linux.vnet.ibm.com>
   Michael Wood         <esiotrot@gmail.com>