configure: remove bashism

Commit e26110cfc67d48 added a check for shacmd to create a hash
for modules.  This check in configure is using bash construct &>
to redirect both stdout and stderr, which does fun things on some
shells.  Get rid of it, use standard redirection instead.

Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
Reviewed-by: Fam Zheng <famz@redhat.com>
