phypUUIDTable_Push: do not corrupt output stream upon partial write

* src/phyp/phyp_driver.c (phypUUIDTable_Push): Move incr/decr
of ptr/nread into the loop where those variables are used.
Also, remove "exit" label and just-preceding "goto".

src/phyp/phyp_driver.c

@@ -2002,14 +2002,11 @@ phypUUIDTable_Push(virConnectPtr conn)
                 /* rc indicates how many bytes were written this time */
                 sent += rc;
             }
+            ptr += sent;
+            nread -= sent;
         } while (rc > 0 && sent < nread);
-        ptr += sent;
-        nread -= sent;
     } while (1);
 
-    goto exit;
-
-  exit:
     if (channel) {
         libssh2_channel_send_eof(channel);
         libssh2_channel_wait_eof(channel);