More spec cleanups

mingw-libpng.spec

@@ -67,7 +67,7 @@ This package contains static cross-compiled libraries.
 
 
 %prep
-%setup -q -n libpng-%{version}
+%autosetup -p1 -n libpng-%{version}
 
 
 %build
@@ -76,15 +76,15 @@ This package contains static cross-compiled libraries.
 
 
 %install
-%mingw_make_install DESTDIR=$RPM_BUILD_ROOT
+%mingw_make_install
 
 # Drop all .la files
-find $RPM_BUILD_ROOT -name "*.la" -delete
+find %{buildroot} -name "*.la" -delete
 
 # No need to distribute manpages which appear in the Fedora
 # native packages already.
-rm -rf $RPM_BUILD_ROOT%{mingw32_mandir}
-rm -rf $RPM_BUILD_ROOT%{mingw64_mandir}
+rm -rf %{buildroot}%{mingw32_mandir}
+rm -rf %{buildroot}%{mingw64_mandir}
 
 
 # Win32