Avoid using %zu or %zd with printf() and fprintf().

This prevents problems on systems where the system printf(3) is not
C99-compliant.  We use our own snprintf() on such systems so that
is safe.

plugins/python/regress/iohelpers.c

@@ -22,6 +22,7 @@
  */
 
 #include "iohelpers.h"
+#include <sudo_fatal.h>
 
 int
 rmdir_recursive(const char *path)
@@ -69,7 +70,7 @@ freadall(const char *file_path, char *output, size_t max_len)
     int rc = false;
     FILE *file = fopen(file_path, "rb");
     if (file == NULL) {
-        printf("Failed to open file '%s'\n", file_path);
+	sudo_warn_nodebug("failed to open file '%s'", file_path);
         goto cleanup;
     }
 
@@ -77,12 +78,13 @@ freadall(const char *file_path, char *output, size_t max_len)
     output[len] = '\0';
 
     if (ferror(file) != 0) {
-        printf("Failed to read file '%s' (Error %d)\n", file_path, ferror(file));
+        sudo_warn_nodebug("failed to read file '%s'", file_path);
         goto cleanup;
     }
 
     if (!feof(file)) {
-        printf("File '%s' was bigger than allocated buffer %zu", file_path, max_len);
+        sudo_warn_nodebug("file '%s' was bigger than allocated buffer %zu",
+	    file_path, max_len);
         goto cleanup;
     }