Fixing silly using #elif instead of #else...

Author: fionn-r

Adafruit_BusIO_Register.h

@@ -80,7 +80,7 @@ class Adafruit_BusIO_Register {
 #if !defined(NO_GLOBAL_INSTANCES) && !defined(NO_GLOBAL_SERIAL)
   void print(Stream *s = &Serial);
   void println(Stream *s = &Serial);
-#elif
+#else
   void print(Stream *s);
   void println(Stream *s);
 #endif