scripts/rpc.py: explicitly en/decode socket data

This is required to work on Python 3.

Change-Id: I1893d967027e3ccebfc6a796dcffa59209d477f9
Signed-off-by: Daniel Verkamp <daniel.verkamp@intel.com>
Reviewed-on: https://review.gerrithub.io/404434
Reviewed-by: Paul Luse <paul.e.luse@intel.com>
Tested-by: SPDK Automated Test System <sys_sgsw@intel.com>
Reviewed-by: Shuhei Matsumoto <shuhei.matsumoto.xt@hitachi.com>
Reviewed-by: Jim Harris <james.r.harris@intel.com>

scripts/rpc/client.py

@@ -41,7 +41,7 @@ class JSONRPCClient(object):
             print("request:")
             print(json.dumps(req, indent=2))
 
-        self.sock.sendall(reqstr)
+        self.sock.sendall(reqstr.encode("utf-8"))
         buf = ''
         closed = False
         response = {}
@@ -58,7 +58,7 @@ class JSONRPCClient(object):
                 if (newdata == b''):
                     closed = True
 
-                buf += newdata
+                buf += newdata.decode("utf-8")
                 response = json.loads(buf)
             except socket.timeout:
                 break