s3/passdb: clang: Fix 'Value stored during initialization is never read'

s3/passdb: clang: Fix 'Value stored during initialization is never read'

Fixes:

source3/passdb/pdb_interface.c:65:34: warning: Value stored to 'entry' during its initialization is never read <--[clang]
        struct pdb_init_function_entry *entry = backends;
                                        ^~~~~   ~~~~~~~~

/source3/passdb/pdb_interface.c:140:11: warning: Value stored to 'nt_status' during its initialization is never read <--[clang]
        NTSTATUS nt_status = NT_STATUS_UNSUCCESSFUL;
                 ^~~~~~~~~   ~~~~~~~~~~~~~~~~~~~~~~
2 warnings generated.

Signed-off-by: Noel Power <noel.power@suse.com>
Reviewed-by: Jeremy Allison <jra@samba.org>