Remove BuildRoot definition

None of currently supported distributions need that.
It was needed last for EL5 which is EOL now

Signed-off-by: Igor Gnatenko <ignatenkobrain@fedoraproject.org>

libsvm.spec

@@ -27,7 +27,6 @@ Patch1:         %{name}.pythonDir.patch
 Patch2:         %{name}.javaDir.patch
 Patch3:         %{name}.svm-toy.patch
 Patch4:         %{name}.toolsDir.patch
-BuildRoot:      %{_tmppath}/%{name}-%{version}-%{release}-root
 BuildRequires:  grep
 
 %if 0%{?rhel} != 0 && 0%{?rhel} <= 5