8247863: Unreachable code in OperatingSystemImpl.getTotalSwapSpaceSize()

After 8231111 we have -1 for missing metrics, thus the fix of 8236617 is obsolete

Reviewed-by: mbaesken

src/jdk.management/unix/classes/com/sun/management/internal/OperatingSystemImpl.java

@@ -61,8 +61,7 @@ class OperatingSystemImpl extends BaseOperatingSystemImpl
             // it can use as much memory as the host's OS allows.
             long memLimit = containerMetrics.getMemoryLimit();
             if (limit >= 0 && memLimit >= 0) {
-                // we see a limit == 0 on some machines where "kernel does not support swap limit capabilities"
-                return (limit < memLimit) ? 0 : limit - memLimit;
+                return limit - memLimit; // might potentially be 0 for limit == memLimit
             }
         }
         return getTotalSwapSpaceSize0();