perf sort: Use mmap->prot on "dcacheline" formatting

perf sort: Use mmap->prot on "dcacheline" formatting

To match the kernel when setting the PERF_RECORD_MISC_MMAP_DATA bit
in perf_event_attr.header.misc, that gets set when VM_EXEC is not
set in the vm_flags.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.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-r1z0tbdc7tich469aw4szinx@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>