fix: avoid nil dereference in symbol uploader when temp file creation fails

When os.Create fails in attemptUpload, f is nil. The error handler
called os.Remove(f.Name()), which panics with a nil pointer
dereference. Remove the call — there is no file to clean up when
creation fails, and the defer on the success path already handles it.

Author: deadmanoz

reporter/parca_uploader.go

@@ -275,7 +275,6 @@ func (u *ParcaSymbolUploader) attemptUpload(ctx context.Context, fileID libpf.Fi
 	} else {
 		f, err := os.Create(filepath.Join(u.tmp, fileID.StringNoQuotes()))
 		if err != nil {
-			os.Remove(f.Name())
 			return fmt.Errorf("create file: %w", err)
 		}
 		defer os.Remove(f.Name())