perf tools: Add missing newline at the end of header file

Add missing newline at the end of file parse-sublevel-options.h.

Thus removing relevant warning reported by checkpatch.

Signed-off-by: Nghia Le <nghialm78@gmail.com>
Reviewed-by: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http //lore.kernel.org/lkml/20210824085947.224062-1-nghialm78@gmail.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>