[lldb][test] Correctly fix break at _dl_debug_state test on arm.

If lldb finds the dynamic linker in the search path or if the binary is linked staticlly, it will fail at `lldbutil.run_break_set_by_symbol` because the breakpoint is resolved. Otherwise, it's not resolved at this point. But we don't care if it's resolved or not. This test cares about if the breakpoint is hit or not after launching.

This changes the num_expected_locations to -2, which means don't assert on if this breakpoint resolved or not.