[gimp/gimp-2-10] plug-ins: get rid of compilation warning.

[Jehan <jehanp src gnome org>]

commit 76f1a02631eb091d6d285f64710efa47f1716e61
Author: Jehan <jehan girinstud io>
Date:   Wed Jun 12 12:54:37 2019 +0200

    plug-ins: get rid of compilation warning.
    
    Note that I am using twice TIFFErrorHandler type. This is because
    TIFFWarningHandler does not exist, despite what the docs says and
    upstream code actually uses twice the same handler type.
    
    (cherry picked from commit de866d881537a2931197ab4752c0047a5d29f766)

 plug-ins/file-tiff/file-tiff-io.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)
---
diff --git a/plug-ins/file-tiff/file-tiff-io.c b/plug-ins/file-tiff/file-tiff-io.c
index 2405a8970e..7f1c16b373 100644
--- a/plug-ins/file-tiff/file-tiff-io.c
+++ b/plug-ins/file-tiff/file-tiff-io.c
@@ -74,8 +74,8 @@ tiff_open (GFile        *file,
            const gchar  *mode,
            GError      **error)
 {
-  TIFFSetWarningHandler (tiff_io_warning);
-  TIFFSetErrorHandler (tiff_io_error);
+  TIFFSetWarningHandler ((TIFFErrorHandler) tiff_io_warning);
+  TIFFSetErrorHandler ((TIFFErrorHandler) tiff_io_error);
 
   tiff_io.file = file;