patch 8.2.5127: using assert_true() does not show value on failure

Problem:    Using assert_true() does not show value on failure.
Solution:   Use assert_inrange(). (closes #10593)
diff --git a/src/testdir/test_hlsearch.vim b/src/testdir/test_hlsearch.vim
index 8325841..ed50145 100644
--- a/src/testdir/test_hlsearch.vim
+++ b/src/testdir/test_hlsearch.vim
@@ -54,8 +54,7 @@
   let @/ = '\%#=1a*.*X\@<=b*'
   redraw
   let elapsed = reltimefloat(reltime(start))
-  call assert_true(elapsed > min_timeout)
-  call assert_true(elapsed < 1.0)
+  call assert_inrange(min_timeout, 1.0, elapsed)
   set nohlsearch redrawtime&
   bwipe!
 endfunc