patch 9.0.0541: terminal pwd test fails with a very long path name

Problem:    Terminal pwd test fails with a very long path name.
Solution:   Join two lines.
diff --git a/src/testdir/test_terminal.vim b/src/testdir/test_terminal.vim
index fd427fe..e654807 100644
--- a/src/testdir/test_terminal.vim
+++ b/src/testdir/test_terminal.vim
@@ -630,7 +630,9 @@
   endif
   call mkdir('Xtermdir')
   let buf = term_start(cmd, {'cwd': 'Xtermdir'})
-  call WaitForAssert({-> assert_equal('Xtermdir', fnamemodify(getline(1), ":t"))})
+  " if the path is very long it may be split over two lines, join them
+  " together
+  call WaitForAssert({-> assert_equal('Xtermdir', fnamemodify(getline(1) .. getline(2), ":t"))})
 
   exe buf . 'bwipe'
   call delete('Xtermdir', 'rf')