etc/pam.d/Makefile.am: Fix typo

etc/pam.d/Makefile.am: Fix typo

The commit we're fixing mentions that it wanted to move 'chpasswd', but
it removed 'ch_g_passwd' from 'pamd_acct_tools_files' and added
'chpasswd' to 'pamd_files'.  It seems it removed the wrong thing by
accident.

Fixes: 341d80c2c751 ("Makefile: move chpasswd and newusers to pamd target")
Link: <https://github.com/shadow-maint/shadow/pull/928#discussion_r1487687347>
Link: <https://github.com/shadow-maint/shadow/issues/926#issuecomment-1941324761>
Reported-by: Dominique Leuenberger <dleuenberger@suse.com>
Reported-by: Michael Vetter <jubalh@iodoru.org>
Cc: David Runge <dvzrv@archlinux.org>
Reviewed-by: Iker Pedrosa <ipedrosa@redhat.com>
Tested-by: Michael Vetter <jubalh@iodoru.org>
Reviewed-by: Michael Vetter <jubalh@iodoru.org>
Reviewed-by: loqs <https://github.com/loqs>
Co-developed-by: Dominique Leuenberger <dleuenberger@suse.com>
Signed-off-by: Dominique Leuenberger <dleuenberger@suse.com>
Signed-off-by: Alejandro Colomar <alx@kernel.org>