patch 9.1.1255: missing test condition for 'pummaxwidth' setting

Problem:  missing test condition for 'pummaxwidth' setting, pummaxwidth
          not effective when width is 32 and height is 10
          (after v9.1.1250)
Solution: add missing comparison condition in pum_width()
          (glepnir)

closes: #16999

Signed-off-by: glepnir <glephunter@gmail.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/src/testdir/test_popup.vim b/src/testdir/test_popup.vim
index 94839b5..e95465c 100644
--- a/src/testdir/test_popup.vim
+++ b/src/testdir/test_popup.vim
@@ -2017,6 +2017,11 @@
   call VerifyScreenDump(buf, 'Test_pum_maxwidth_04', {'rows': 8})
   call term_sendkeys(buf, "\<Esc>3Gdd\"zp")
 
+  call term_sendkeys(buf, ":set lines=10 columns=32\<CR>")
+  call term_sendkeys(buf, "GA\<C-N>")
+  call VerifyScreenDump(buf, 'Test_pum_maxwidth_09', {'rows': 10, 'cols': 32})
+  call term_sendkeys(buf, "\<Esc>3Gdd\"zp")
+
   call StopVimInTerminal(buf)
 endfunc