Use the same pre-release version helpers as in other GNOME packages

adwaita-icon-theme.spec

@@ -1,6 +1,8 @@
 # Set boostrap to 1 for initial bootstrapping when gtk3 is not yet built
 %global bootstrap 0
 
+%global tarball_version %%(echo %{version} | tr '~' '.')
+
 Name:           adwaita-icon-theme
 Version:        40.0~rc
 Release:        1%{?dist}
@@ -8,7 +10,7 @@ Summary:        Adwaita icon theme
 
 License:        LGPLv3+ or CC-BY-SA
 URL:            http://www.gnome.org
-Source0:        http://download.gnome.org/sources/adwaita-icon-theme/40/%{name}-40.rc.tar.xz
+Source0:        http://download.gnome.org/sources/adwaita-icon-theme/40/%{name}-%{tarball_version}.tar.xz
 
 BuildArch:      noarch
 
@@ -40,7 +42,7 @@ The %{name}-devel package contains the pkgconfig file for
 developing applications that use %{name}.
 
 %prep
-%autosetup -p1 -n %{name}-40.rc
+%autosetup -p1 -n %{name}-%{tarball_version}
 
 %build
 %configure