I think you're still missing it:
Pre-process runs and part of it's output is this:
-1 findbugs 0m 26s hadoop-common-project/hadoop-kms in trunk has 2 extant Findbugs warnings.
i.e., trunk has 2 existing findbugs issues
Yetus then starts on it's second pass with the patch in place (the mvninstall lines are good indicators where it is). It then provides this output:
+1 findbugs 0m 34s hadoop-common-project/hadoop-kms generated 0 new + 0 unchanged - 2 fixed = 0 total (was 2)
.... which indicates the patch fixed the 2 findbugs issues.