[giggle] Fix build failure with gcc-10

[Javier Jardón Cabezas <jjardon src gnome org>]

commit 57fd690279c4f8f0a367ec4f3599ab3a8159be49
Author: Sudip Mukherjee <sudipm mukherjee gmail com>
Date:   Thu Apr 23 19:18:37 2020 +0100

    Fix build failure with gcc-10
    
    It fails to build while building with gcc-10 with the error:
    multiple definition of `giggle_diff_style'
    
    giggle_diff_style is passed to g_enum_register_static() register the
    static enumeration type with the given name and it should be done
    as a typedef.
    
    Fixes #11
    
    Bug-Link: https://bugs.debian.org/bug=957269
    Signed-off-by: Sudip Mukherjee <sudipm mukherjee gmail com>

 src/giggle-diff-view.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/src/giggle-diff-view.h b/src/giggle-diff-view.h
index 28266e3..3cba760 100644
--- a/src/giggle-diff-view.h
+++ b/src/giggle-diff-view.h
@@ -34,7 +34,7 @@ G_BEGIN_DECLS
 #define GIGGLE_IS_DIFF_VIEW_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE ((klass), GIGGLE_TYPE_DIFF_VIEW))
 #define GIGGLE_DIFF_VIEW_GET_CLASS(obj)  (G_TYPE_INSTANCE_GET_CLASS ((obj), GIGGLE_TYPE_DIFF_VIEW, 
GiggleDiffViewClass))
 
-enum {
+typedef enum {
        STYLE_CHUNK,
        STYLE_FILE,
        STYLE_ALL,