tests: robustify -w option test

* tests/count.test: Allow nanosleep to spend a bit less time than 1 second.
diff --git a/tests/count.test b/tests/count.test
index bc7ae7c..e9eafd9 100755
--- a/tests/count.test
+++ b/tests/count.test
@@ -35,10 +35,10 @@
 
 args='-cw sleep 1'
 make_log
-grep_log ' *[^ ]+ +1\.0[^n]*nanosleep'
+grep_log ' *[^ ]+ +(1\.0|0\.99)[^n]*nanosleep'
 
 args='-cw -enanosleep sleep 1'
 make_log
-grep_log '100\.00 +1\.0[^n]*nanosleep'
+grep_log '100\.00 +(1\.0|0\.99)[^n]*nanosleep'
 
 exit 0