edit to description of run_test_compare()

README.md

@@ -153,10 +153,9 @@ above, but that takes a void pointer as a second argument.  Finally,
 the third argument is the pointer that gets passed into the test
 function.
 
-`run_test_compare()` is similar, but it allows two pointers to be
-passed into the test.  This is useful for comparing an actual value to
-an expected one, for instance comparing the actual output from a
-function to an expected value.
+`run_test_compare()` is similar, but it allows *two* pointers to be
+passed into the test.  This is useful for comparing the actual output
+of a function to an expected value, for instance.
 
 The prototype for `run_test_compare()` follows: