ttk/notebook.test: move test setup statements in notebook-5.1 to a COMMON TEST SETUP section

Author: 1minus1is0

tests/ttk/notebook.test

@@ -56,7 +56,7 @@ inoperative test notebook-1.2 "Cannot add siblings" -body {
 test notebook-1.3 "Cannot add toplevel" -body {
     .nb add [toplevel .nb.t]
 } -cleanup {
-    destroy .t.nb
+    destroy .nb.t
 } -returnCodes error -result {cannot add ".nb.t" as content of ".nb"}
 
 test notebook-1.4 "Try to select bad tab" -body {
@@ -123,13 +123,17 @@ test notebook-4.4 "-padding option" -body {
 
 test notebook-4.end "Cleanup test suite 1-4.*" -body { destroy .nb }
 
-test notebook-5.1 "Virtual events" -body {
-    toplevel .t
-    update
-    set ::events [list]
-    pack [set nb [ttk::notebook .t.nb]] -expand true -fill both; update
-    bind .t <<NotebookTabChanged>> { lappend events changed %W }
+#
+# COMMON TEST SETUP
+#
+toplevel .t
+update
+set nb [ttk::notebook .t.nb]
+pack $nb -expand true -fill both; update
+bind .t <<NotebookTabChanged>> { lappend events changed %W }
 
+test notebook-5.1 "Virtual events" -body {
+    set events [list]
     $nb add [frame $nb.f1] ;  # triggers <<NotebookTabChanged>> (first tab gets autoselected)
     $nb add [frame $nb.f2]
     $nb add [frame $nb.f3]