perf tools: Fix up /proc/PID/maps parsing

When introducing support for MMAP2 we considered more parts of each map
representation in /proc/PID/maps, and when disabling it we forgot to
reduce the number of expected parsed/assigned entries in the sscanf
call, fix it to expect the right number of desired fields, 5.

Reported-by: Markus Trippelsdorf <markus@trippelsdorf.de>
Based-on-a-patch-by: Markus Trippelsdorf <markus@trippelsdorf.de>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-vrbo1wik997ahjzl1chm3bdm@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/util/event.c

@@ -213,7 +213,7 @@ static int perf_event__synthesize_mmap_events(struct perf_tool *tool,
 		       &event->mmap.pgoff,
 		       execname);
 
-		if (n != 8)
+		if (n != 5)
 			continue;
 
 		if (prot[2] != 'x')