Fix typo of variable name

protocol/pjrc/usb_keyboard.c

@@ -39,7 +39,7 @@ uint8_t keyboard_protocol=1;
 // the idle configuration, how often we send the report to the
 // host (ms * 4) even when it hasn't changed
 // Windows and Linux set 0 while OS X sets 6(24ms) by SET_IDLE request.
-uint8_t keyobard_idle=125;
+uint8_t keyboard_idle=125;
 
 // count until idle timeout
 uint8_t usb_keyboard_idle_count=0;