RPM packaging: use %global inside %{!?...}

According to
https://www.redhat.com/archives/fedora-devel-list/2010-January/msg00093.html

scope of %define lasts until the end brace; earlier RPM up to Fedora 12
didn't necessarily honor the scope, but later versions corrected the bug.

Problem and solution both pointed out by Todd Zullinger.

Signed-off-by: Junio C Hamano <gitster@pobox.com>

git.spec.in

@@ -98,7 +98,7 @@ BuildRequires:  perl(Error)
 Perl interface to Git
 
 %define path_settings ETC_GITCONFIG=/etc/gitconfig prefix=%{_prefix} mandir=%{_mandir} htmldir=%{_docdir}/%{name}-%{version}
-%{!?python_sitelib: %define python_sitelib %(%{__python} -c "from distutils.sysconfig import get_python_lib; print get_python_lib()")}
+%{!?python_sitelib: %global python_sitelib %(%{__python} -c "from distutils.sysconfig import get_python_lib; print get_python_lib()")}
 
 %prep
 %setup -q
@@ -192,6 +192,9 @@ rm -rf $RPM_BUILD_ROOT
 # No files for you!
 
 %changelog
+* Sun Jan 31 2010 Junio C Hamano <gitster@pobox.com>
+- Do not use %define inside %{!?...} construct.
+
 * Sat Jan 30 2010 Junio C Hamano <gitster@pobox.com>
 - We don't ship Python bits until a real foreign scm interface comes.