perf tools: Fix possible (unlikely) buffer overflow

cppcheck reported:
[tools/perf/util/sysfs.c:50]: (error) Width 4096 given in format string
(no. 1) is larger than destination buffer 'sysfs_mountpoint[4096]',
use %4095s to prevent overflowing it

-> All other places in the kernel that use STR(PATH_MAX)
   have a buffer size of PATH_MAX + 1.

Signed-off-by: Thomas Jarosch <thomas.jarosch@intra2net.com>
Link: http://lkml.kernel.org/r/50D9D30B.8090002@intra2net.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/util/sysfs.c

@@ -8,7 +8,7 @@ static const char * const sysfs_known_mountpoints[] = {
 };
 
 static int sysfs_found;
-char sysfs_mountpoint[PATH_MAX];
+char sysfs_mountpoint[PATH_MAX + 1];
 
 static int sysfs_valid_mountpoint(const char *sysfs)
 {