We've had this in 'perf top' for quite a while, useful if one wishes
to force using /proc/kcore to do annotation using the patched kernel
instead of the ELF image it started from, aka vmlinux.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jin Yao <yao.jin@linux.intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: https://lkml.kernel.org/n/tip-ircpvox4wzsv7gasrpb28fw9@git.kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>