papi: fix socket sendall calls

No point in checking the return value,
as .sendall() raises on error
(and the previous check was missing "not").

Type: fix

Change-Id: I9e07709ddd7093f91ffef87808abbab264b8aa5a
Signed-off-by: Vratko Polak <vrpolak@cisco.com>

src/vpp-api/python/vpp_papi/vpp_transport_socket.py

@@ -188,10 +188,12 @@ class VppTransport(object):
 
         # Send header
         header = self.header.pack(0, len(buf), 0)
-        if self.socket.sendall(header) is None:
-            raise VppTransportSocketIOError(1, 'Failed to send')
-        if self.socket.sendall(buf) is None:
-            raise VppTransportSocketIOError(1, 'Failed to send')
+        try:
+            self.socket.sendall(header)
+            self.socket.sendall(buf)
+        except socket.error as err:
+            raise VppTransportSocketIOError(1, 'Sendall error: {err!r}'.format(
+                err=err))
 
     def _read_fixed(self, size):
         """Repeat receive until fixed size is read. Return empty on error."""