fix(from_entry): skip validation with unnamed buffer

Author: v1nns

lua/telescope/from_entry.lua

@@ -26,7 +26,7 @@ function from_entry.path(entry, validate, escape)
   end
 
   -- only 0 if neither filereadable nor directory
-  if validate then
+  if validate and path ~= "[No Name]" then
     -- We need to expand for filereadable and isdirectory
     -- TODO(conni2461): we are not going to return the expanded path because
     --                  this would lead to cache misses in the perviewer.