libusbx52: Clean up compiler warnings

lib/libusbx52/fopen_env.c

@@ -9,6 +9,7 @@
 
 #include <stdio.h>
 #include <stdlib.h>
+#include "libusbx52.h"
 
 FILE * fopen_env(const char *env, const char *env_default, const char *mode)
 {

lib/libusbx52/usb_x52_stub.c

@@ -21,7 +21,7 @@ int libusb_init(libusb_context **ctx)
     unsigned int vid;
     unsigned int pid;
     int parsed;
-    FILE *dev_list;
+    FILE *dev_list = NULL;
     int i;
 
     /*
@@ -236,10 +236,11 @@ int libusb_open(libusb_device *dev, libusb_device_handle **handle)
 
 void libusb_close(libusb_device_handle *dev_handle)
 {
+    libusb_device *dev;
     /* Decrement the refcount for the underlying device */
     dev_handle->dev->ref_count -= 1;
 
-    libusb_device *dev = dev_handle->dev;
+    dev = dev_handle->dev;
     LIBUSB_DUMP_LOG_FILE(dev_handle, LIBUSB_LOG_LEVEL_DEBUG,
         "VID: %04x PID: %04x idx: %d ref: %d\n",
         dev->desc.idVendor, dev->desc.idProduct, dev->index, dev->ref_count);

lib/libusbx52/util/create_device_list.c

@@ -17,7 +17,6 @@
 int main(int argc, char *argv[])
 {
     FILE *data;
-    char **id_pair;
     unsigned int vid;
     unsigned int pid;
     int i;

lib/libusbx52/util/log_actions.c

@@ -82,6 +82,9 @@ int main(int argc, char *argv[])
     libusb_context *ctx;
 
     hdl = libusbx52_init();
+    if (hdl == NULL) {
+        return 1;
+    }
     ctx = hdl->ctx;
 
     /* Process arguments until there are fewer than 2 remaining */