perf machine: Use map as success in ip__resolve_ams

When trying to map a bunch of instruction addresses to their respective
threads, I kept getting a lot of bogus entries [I forget the exact
reason as I patched my code months ago].

Looking through ip__resolve_ams, I noticed the check for

if (al.sym)

and realized, most times I have an al.map definition but sometimes an
al.sym is undefined. In the cases where al.sym is undefined, the loop
keeps going even though a valid al.map exists.

Modify this check to use the more reliable al.map. This fixed my bogus
entries.

Signed-off-by: Don Zickus <[e-mail]>
Cc: Jiri Olsa <[e-mail]>
Cc: Stephane Eranian <[e-mail]>
Link: http://lkml.kernel.org/r/[e-mail]
Signed-off-by: Arnaldo Carvalho de Melo <[e-mail]>

tools/perf/util/machine.c

···
 		 */
 		thread__find_addr_location(thread, machine, m, MAP__FUNCTION,
 				ip, &al);
-		if (al.sym)
+		if (al.map)
 			goto found;
 	}
 found: