perf tests: Fix record+probe_libc_inet_pton.sh for powerpc64

perf tests: Fix record+probe_libc_inet_pton.sh for powerpc64

For powerpc64, this test currently fails due to a mismatch in the
expected output.

This can be observed on a powerpc64le system running Fedora 27 as shown
below.

  # perf test -v "probe libc's inet_pton & backtrace it with ping"

Before:

  62: probe libc's inet_pton & backtrace it with ping       :
  --- start ---
  test child forked, pid 23948
  ping 23965 [003] 71136.075084: probe_libc:inet_pton: (7fff996aaf28)
  7fff996aaf28 __GI___inet_pton+0x8 (/usr/lib64/libc-2.26.so)
  7fff9965fa54 gaih_inet.constprop.7+0xf44 (/usr/lib64/libc-2.26.so)
  FAIL: expected backtrace entry 2 "getaddrinfo\+0x[[:xdigit:]]+[[:space:]]\(/usr/lib64/libc-2.26.so\)$" got "7fff9965fa54 gaih_inet.constprop.7+0xf44 (/usr/lib64/libc-2.26.so)"
  test child finished with -1
  ---- end ----
  probe libc's inet_pton & backtrace it with ping: FAILED!

After:

  62: probe libc's inet_pton & backtrace it with ping       :
  --- start ---
  test child forked, pid 24638
  ping 24655 [001] 71208.525396: probe_libc:inet_pton: (7fffa245af28)
  7fffa245af28 __GI___inet_pton+0x8 (/usr/lib64/libc-2.26.so)
  7fffa240fa54 gaih_inet.constprop.7+0xf44 (/usr/lib64/libc-2.26.so)
  7fffa24105b4 getaddrinfo+0x164 (/usr/lib64/libc-2.26.so)
  138d52d70 main+0x3e0 (/usr/bin/ping)
  test child finished with 0
  ---- end ----
  probe libc's inet_pton & backtrace it with ping: Ok

Signed-off-by: Sandipan Das <sandipan@linux.ibm.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Kim Phillips <kim.phillips@arm.com>
Cc: Maynard Johnson <maynard@us.ibm.com>
Cc: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Cc: Ravi Bangoria <ravi.bangoria@linux.vnet.ibm.com>
Cc: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Fixes: e07d585e2454 ("perf tests: Switch trace+probe_libc_inet_pton to use record")
Link: http://lkml.kernel.org/r/49621ec5f37109f0655e5a8c32287ad68d85a1e5.1530724939.git.sandipan@linux.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>