Fix button text overlapping with shortcut text in popups

The purpose of the keymap strings is probably for un-embossed menu items
like seen in most pulldowns. I can't see a reason for also adding that
string for regularly drawn buttons within popups, we don't add it
anywhere else in the UI either. So this commit makes sure shortcut
strings are only added to buttons that are drawn like pulldown-menu
items.

source/blender/editors/interface/interface.c

@@ -1165,6 +1165,8 @@ static void ui_menu_block_set_keymaps(const bContext *C, uiBlock *block)
 	uiBut *but;
 	char buf[128];
 
+	BLI_assert(block->flag & UI_BLOCK_LOOP);
+
 	/* only do it before bounding */
 	if (block->rect.xmin != block->rect.xmax)
 		return;
@@ -1179,6 +1181,9 @@ static void ui_menu_block_set_keymaps(const bContext *C, uiBlock *block)
 	}
 	else {
 		for (but = block->buttons.first; but; but = but->next) {
+			if (but->dt != UI_EMBOSS_PULLDOWN) {
+				continue;
+			}
 
 			if (ui_but_event_operator_string(C, but, buf, sizeof(buf))) {
 				ui_but_add_shortcut(but, buf, false);