Fix autoconf detection of super_setup_bdi_name

Fix autoconf detection of super_setup_bdi_name

The previous autoconf test for the presence of super_setup_bdi_name()
uses an invocation with an incorrect type signature, producing a
warning by the compiler when the test is run. This gets elevated to an
error when compiling with -Werror=format-security, causing autoconf to
falsely infer super_setup_bdi_name() is not present. This updates the
testing code to match the invocation used in
include/linux/vfs_compat.h.

Reviewed-by: loli10K <ezomori.nozomu@gmail.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Justin Bedo <cu@cua0.org>
Closes #6398