patch 8.2.1886: using ":silent!" in a popup filter has unexpected effect

Problem:    Using ":silent!" in a popup filter has unexpected effect.
Solution:   Use did_emsg instead of called_emsg. (closes #7178)
diff --git a/src/testdir/test_popupwin.vim b/src/testdir/test_popupwin.vim
index 1524e78..435873e 100644
--- a/src/testdir/test_popupwin.vim
+++ b/src/testdir/test_popupwin.vim
@@ -2158,6 +2158,7 @@
     endfunc
     func Popup_filter(winid, key)
       if a:key == 'j'
+	silent! this_throws_an_error_but_is_ignored
 	let line = popup_getoptions(a:winid).firstline
 	let nlines = line('$', a:winid)
 	let newline = line < nlines ? (line + 1) : nlines