[babl] extensions: gggl: conv_rgb8_rgba8(): use 255UL, not 255

[Øyvind Kolås <ok src gnome org>]

commit e5af4d543a26da24d389aa80a1111ad49100c3fd
Author: Roman Lebedev <lebedev ri gmail com>
Date:   Fri Aug 19 20:05:17 2016 +0300

    extensions: gggl: conv_rgb8_rgba8(): use 255UL, not 255
    
    Fixes:
    gggl.c:758:62: runtime error: left shift of 255 by 24 places cannot be represented in type 'int'

 extensions/gggl.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/extensions/gggl.c b/extensions/gggl.c
index 7ab4400..c4b8ce4 100644
--- a/extensions/gggl.c
+++ b/extensions/gggl.c
@@ -755,7 +755,7 @@ conv_rgb8_rgba8 (unsigned char *src, unsigned char *dst, long samples)
   long n = samples-1;
   while (n--)
     {
-      *(unsigned int *) dst = (*(unsigned int *) src) | (255 << 24);
+      *(unsigned int *) dst = (*(unsigned int *) src) | (255UL << 24);
       src   += 3;
       dst   += 4;
     }