curl: fix callback functions to match prototype

The function tool_debug_cb doesn't match curl_debug_callback in curl.h
(unsigned vs. signed char* for 3rd param).

Bug: https://curl.haxx.se/mail/lib-2017-03/0120.html

Author: hannob

src/tool_cb_dbg.c

@@ -41,7 +41,7 @@ static void dump(const char *timebuf, const char *text,
 */
 
 int tool_debug_cb(CURL *handle, curl_infotype type,
-                  unsigned char *data, size_t size,
+                  char *data, size_t size,
                   void *userdata)
 {
   struct OperationConfig *operation = userdata;
@@ -209,7 +209,8 @@ int tool_debug_cb(CURL *handle, curl_infotype type,
     break;
   }
 
-  dump(timebuf, text, output, data, size, config->tracetype, type);
+  dump(timebuf, text, output, (unsigned char *) data, size, config->tracetype,
+       type);
   return 0;
 }
 

src/tool_cb_dbg.h

@@ -28,7 +28,7 @@
 */
 
 int tool_debug_cb(CURL *handle, curl_infotype type,
-                  unsigned char *data, size_t size,
+                  char *data, size_t size,
                   void *userdata);
 
 #endif /* HEADER_CURL_TOOL_CB_DBG_H */