Fixed some more simple compile warnings in the examples.

docs/examples/sepheaders.c

@@ -16,7 +16,7 @@
 #include <curl/types.h>
 #include <curl/easy.h>
 
-size_t write_data(void *ptr, size_t size, size_t nmemb, void *stream)
+static size_t write_data(void *ptr, size_t size, size_t nmemb, void *stream)
 {
   int written = fwrite(ptr, size, nmemb, (FILE *)stream);
   return written;