perf annotate: Simplify disasm_line allocation and freeing code

perf annotate: Simplify disasm_line allocation and freeing code

We are allocating disasm_line object in annotation_line__new() instead
of disasm_line__new(). Similarly annotation_line__delete() is actually
freeing disasm_line object as well. This complexity is because of
privsize.  But we don't need privsize anymore so get rid of privsize and
simplify disasm_line allocation and freeing code.

Signed-off-by: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Jin Yao <yao.jin@linux.intel.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Song Liu <songliubraving@fb.com>
Link: http://lore.kernel.org/lkml/20200204045233.474937-3-ravi.bangoria@linux.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>