Fix backported from to 5.0.
"Remove the alignment option, let valgrind use its default"


mysql-test/mysql-test-run-shell.sh:
  Bug #47811 : remove the non-default alignment specification.
    - backport from 5.1
     "Remove the alignment option, let valgrind use its default"
mysql-test/mysql-test-run.pl:
  Bug #47811 : remove the non-default alignment specification.
    - backport from 5.1
     "Remove the alignment option, let valgrind use its default"