[lldb/test] Reformat Objective-C data-formatter source file (NFC)

The source file used to test Objective-C data-formatters didn't respected
any formatting (mixed tab and spaces, lines exceed column 80, etc...).

This patch reformats the file using clang-format to make it easier to
work with.

Signed-off-by: Med Ismail Bennani <medismail.bennani@gmail.com>