use easier tag macros to make both fedora and debbuild happy

Signed-off-by: Lokesh Mandvekar <lsm5@fedoraproject.org>

conmon.spec

@@ -8,7 +8,7 @@
 %global debug_package %{nil}
 %endif
 
-%global built_tag v2.1.3
+%global built_tag_strip 2.1.3
 
 Name: conmon
 Epoch: 2
@@ -23,7 +23,7 @@ Release: %autorelease
 %endif
 Summary: OCI container runtime monitor
 URL: https://github.com/containers/%{name}
-Source0: %{url}/archive/%{built_tag}.tar.gz
+Source0: %{url}/archive/v%{built_tag_strip}.tar.gz
 BuildRequires: go-md2man
 %if "%{_vendor}" == "debbuild"
 BuildRequires: git
@@ -49,7 +49,7 @@ Requires: libseccomp
 %{summary}.
 
 %prep
-%autosetup -Sgit
+%autosetup -Sgit %{name}-%{built_tag_strip}
 sed -i 's/install.bin: bin\/conmon/install.bin:/' Makefile
 sed -i 's/install.crio: bin\/conmon/install.crio:/' Makefile