This 'perf test' case fails on s390x. The 'touch' command on s390x uses
the 'openat' system call to open the file named on the command line:

[root@s35lp76 perf]# perf probe -l
  probe:vfs_getname    (on getname_flags:72@fs/namei.c with pathname)
[root@s35lp76 perf]# perf trace -e open touch /tmp/abc
     0.400 ( 0.015 ms): touch/27542 open(filename:
		/usr/lib/locale/locale-archive, flags: CLOEXEC) = 3
[root@s35lp76 perf]#

There is no 'open' system call for file '/tmp/abc'. Instead the 'openat'
system call is used:

[root@s35lp76 perf]# strace touch /tmp/abc
    execve("/usr/bin/touch", ["touch", "/tmp/abc"], 0x3ffd547ec98
			/* 30 vars */) = 0
    [...]
    openat(AT_FDCWD, "/tmp/abc", O_WRONLY|O_CREAT|O_NOCTTY|O_NONBLOCK, 0666) = 3
    [...]

On s390x the 'egrep' command does not find a matching pattern and
returns an error.

Fix this for s390x create a platform dependent command line to enable
the 'perf probe' call to listen to the 'openat' system call and get the
expected output.
Signed-off-by: Thomas-Mich Richter <tmricht@linux.vnet.ibm.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Cc: Thomas-Mich Richter <tmricht@linux.vnet.ibm.com>
LPU-Reference: 20171114071847.2381-1-tmricht@linux.vnet.ibm.com
Link: http://lkml.kernel.org/n/tip-3qf38jk0prz54rhmhyu871my@git.kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>