rename hid_init() to hidapi_hid_init() to avoid collision with usbhid

Index: hidapi/hidapi.h
--- hidapi/hidapi.h.orig
+++ hidapi/hidapi.h
@@ -197,7 +197,7 @@ extern "C" {
 				This function returns 0 on success and -1 on error.
 				Call hid_error(NULL) to get the failure reason.
 		*/
-		int HID_API_EXPORT HID_API_CALL hid_init(void);
+		int HID_API_EXPORT HID_API_CALL hidapi_hid_init(void);
 
 		/** @brief Finalize the HIDAPI library.