TestTargetProperties: fix typo in cpu reservation

This is just a comment fix, but as I was looking through the code
to see how this tag is implemented, the difference between this
comment and the [documented syntax](https://docs.bazel.build/versions/master/test-encyclopedia.html#other-resources)
confused me.

Closes bazelbuild#12243.

PiperOrigin-RevId: 337231628

src/main/java/com/google/devtools/build/lib/analysis/test/TestTargetProperties.java

@@ -165,7 +165,7 @@ public ResourceSet getLocalResourceUsage(Label label, boolean usingLocalTestJobs
 
     ResourceSet testResourcesFromSize = TestTargetProperties.getResourceSetFromSize(size);
 
-    // Tests can override their CPU reservation with a "cpus:<n>" tag.
+    // Tests can override their CPU reservation with a "cpu:<n>" tag.
     ResourceSet testResourcesFromTag = null;
     for (String tag : executionInfo.keySet()) {
       try {