build: use _topdir macro instead of hardcoded relative path

Author: aikawayataro

build/resources/rpm/SPECS/build.spec

@@ -20,10 +20,10 @@ mkdir -p %{buildroot}/opt/sourcegit
 mkdir -p %{buildroot}/%{_bindir}
 mkdir -p %{buildroot}/usr/share/applications
 mkdir -p %{buildroot}/usr/share/icons
-cp -f ../../../SourceGit/* %{buildroot}/opt/sourcegit/
+cp -f %{_topdir}/../../SourceGit/* %{buildroot}/opt/sourcegit/
 ln -rsf %{buildroot}/opt/sourcegit/sourcegit %{buildroot}/%{_bindir}
-cp -r ../../_common/applications %{buildroot}/%{_datadir}
-cp -r ../../_common/icons %{buildroot}/%{_datadir}
+cp -r %{_topdir}/../_common/applications %{buildroot}/%{_datadir}
+cp -r %{_topdir}/../_common/icons %{buildroot}/%{_datadir}
 chmod 755 -R %{buildroot}/opt/sourcegit
 chmod 755 %{buildroot}/%{_datadir}/applications/sourcegit.desktop