perf machine: Fix paranoid check in machine__set_kernel_mmap()

The machine__set_kernel_mmap() is to setup addresses of the kernel map
using external info.  But it has a check when the address is given from
an incorrect input which should have the start and end address of 0
(i.e. machine__process_kernel_mmap_event).

But we also use the end address of 0 for a valid input so change it to
check both start and end addresses.
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: kernel-team@lge.com
Link: http://lkml.kernel.org/r/20180219101936.GD1583@sejongSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/util/machine.c

@@ -1226,7 +1226,7 @@ static void machine__set_kernel_mmap(struct machine *machine,
 		 * Be a bit paranoid here, some perf.data file came with
 		 * a zero sized synthesized MMAP event for the kernel.
 		 */
-		if (machine->vmlinux_maps[i]->end == 0)
+		if (start == 0 && end == 0)
 			machine->vmlinux_maps[i]->end = ~0ULL;
 	}
 }