tests: recheck: work properly when the test suite was interrupted

* tests/local.mk (recheck): Look at the per-test logs, not the overall
log, which, when interrupted, contains only information about... the
tests that passed.

tests/local.mk

@@ -96,10 +96,10 @@ clean-local-tests:
 
 .PHONY: recheck
 recheck: $(RUN_TESTSUITE_deps)
-	$(RUN_TESTSUITE)							\
-	  $$(perl -n								\
-	     -e 'if (/Summary of the failures/../Detailed failed tests/)'	\
-	     -e '{ /^ *[0-9]+:/ && s/:.*//s && print }' %D%/testsuite.log)
+	$(RUN_TESTSUITE)					\
+	  $$(perl -n						\
+	     -e 'eof && /^(\d+).*: FAILED/ && print "$$1 "'	\
+	        %D%/testsuite.dir/*/testsuite.log)
 
 check-local: $(RUN_TESTSUITE_deps)
 	$(RUN_TESTSUITE)