cppcheck: zerodivcond

I don't know if it can happen or if it's a false positive
but at least, we're sure now it won't fail

Change-Id: Id4620d74c0893b308b9fb45be71ca6c425066ae4
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/109470
Tested-by: Jenkins
Reviewed-by: Julien Nabet <serval2412@yahoo.fr>

sal/osl/unx/process.cxx

@@ -1067,7 +1067,7 @@ oslProcessError SAL_CALL osl_getProcessInfo(oslProcess Process, oslProcessData F
                 unsigned long systemseconds;
 
                 clktck = sysconf(_SC_CLK_TCK);
-                if (clktck < 0) {
+                if (clktck <= 0) {
                     return osl_Process_E_Unknown;
                 }
                 hz = static_cast<unsigned long>(clktck);