Fix a brunch of -Wextra warnings:

- 'static' is not at beginning of declaration;
  - unused parameter;
  - comparison between signed and unsigned.

examples/nfcip-initiator.c

@@ -26,6 +26,7 @@
   #include "config.h"
 #endif // HAVE_CONFIG_H
 
+#include <err.h>
 #include <stdio.h>
 #include <string.h>
 #include <nfc/nfc.h>
@@ -40,6 +41,10 @@ int main(int argc, const char *argv[])
   size_t szRecvBits;
   byte_t send[] = "Hello World!";
 
+  if (argc > 1) {
+    errx (1, "usage: %s", argv[0]);
+  }
+
   pnd = nfc_connect(NULL);
   if (!pnd || !nfc_initiator_init(pnd)
       || !nfc_initiator_select_dep_target(pnd, NM_PASSIVE_DEP, NULL, 0,