[gnome-software] trivial: Fix "void function should not return a value"

[Michael Catanzaro <mcatanzaro src gnome org>]

commit 19a92d509e2925f832f2ca4cc0a1c9099d81e4e2
Author: Ting-Wei Lan <lantw src gnome org>
Date:   Tue Mar 31 03:03:16 2015 +0800

    trivial: Fix "void function should not return a value"
    
    https://bugzilla.gnome.org/show_bug.cgi?id=747185

 src/gs-category.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/src/gs-category.c b/src/gs-category.c
index 4ccade1..bc656dc 100644
--- a/src/gs-category.c
+++ b/src/gs-category.c
@@ -60,7 +60,7 @@ gs_category_get_size (GsCategory *category)
 void
 gs_category_set_size (GsCategory *category, guint size)
 {
-       g_return_val_if_fail (GS_IS_CATEGORY (category), 0);
+       g_return_if_fail (GS_IS_CATEGORY (category));
        category->priv->size = size;
 }