perf test: Fix vmlinux failure on s390x

perf test: Fix vmlinux failure on s390x

On s390x perf test 1 failed. It turned out that commit 4a084ecfc821
("perf report: Fix module symbol adjustment for s390x") was incorrect.
The previous implementation in dso__load_sym() is also suitable for
s390x.

Therefore this patch undoes commit 4a084ecfc821.

Signed-off-by: Thomas-Mich Richter <tmricht@linux.vnet.ibm.com>
Cc: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Cc: Zvonko Kosic <zvonko.kosic@de.ibm.com>
Fixes: 4a084ecfc821 ("perf report: Fix module symbol adjustment for s390x")
LPU-Reference: 20170915071404.58398-1-tmricht@linux.vnet.ibm.com
Link: http://lkml.kernel.org/n/tip-5ani7ly57zji7s0hmzkx416l@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>