Remove dead code

Problem reported by Coverity:
at_most: At condition "io_res < 0", the value of "io_res" must be at most -1.
dead_error_condition: The condition "io_res < 0" must be true.
CID 1090328 (#1 of 1): Logically dead code (DEADCODE)
  dead_error_line: Execution cannot reach this expression "0" inside statement "return (io_res < 0) ? io_re...".

libnfc/nfc-emulation.c

@@ -71,6 +71,6 @@ nfc_emulate_target(nfc_device *pnd, struct nfc_emulator *emulator, const int tim
       szRx = res;
     }
   }
-  return (io_res < 0) ? io_res : 0;
+  return io_res;
 }