[librsvg] Add forgotten return value in error case

[Christian Persch <chpe src gnome org>]

commit 84f1ca128e847e003dd7f082d2742b037b645f34
Author: Felix Riemann <friemann gnome org>
Date:   Fri Mar 23 22:03:19 2012 +0100

    Add forgotten return value in error case
    
    Fix GCC warnings when using the -Wreturn-type parameter.
    
    Bug #672725.

 rsvg-cairo-draw.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/rsvg-cairo-draw.c b/rsvg-cairo-draw.c
index e435479..612c227 100644
--- a/rsvg-cairo-draw.c
+++ b/rsvg-cairo-draw.c
@@ -936,7 +936,7 @@ rsvg_cairo_surface_from_pixbuf (const GdkPixbuf *pixbuf)
     surface = cairo_image_surface_create (format, width, height);
     if (cairo_surface_status (surface) != CAIRO_STATUS_SUCCESS) {
         cairo_surface_destroy (surface);
-        return;
+        return NULL;
     }
 
     cairo_pixels = cairo_image_surface_get_data (surface);