Do not build pmt-ehd without libcryptsetup.

Index: libpam-mount-2.14~gited542159/src/Makefile.am
===================================================================
--- libpam-mount-2.14~gited542159.orig/src/Makefile.am	2012-01-15 19:53:46.433246545 +0100
+++ libpam-mount-2.14~gited542159/src/Makefile.am	2012-01-15 19:54:00.089189018 +0100
@@ -9,7 +9,9 @@ moduledir		= @PAM_MODDIR@
 module_LTLIBRARIES	= pam_mount.la
 bin_PROGRAMS		= pmt-fd0ssh pmt-ofl
 sbin_PROGRAMS		= pmvarrun
+if HAVE_LIBCRYPTSETUP
 sbin_PROGRAMS		+= pmt-ehd
+endif
 ssbin_PROGRAMS		= mount.crypt
 noinst_PROGRAMS		= autoloop
 noinst_SCRIPTS 		= umount.crypt
@@ -71,8 +73,10 @@ autoloop_LDADD		= libcryptmount.la ${lib
 mount_crypt_SOURCES	= mtcrypt.c spawn.c
 mount_crypt_LDADD	= libcryptmount.la libpmt_mtab.la ${libHX_LIBS}
 
+if HAVE_LIBCRYPTSETUP
 pmt_ehd_SOURCES		= ehd.c bdev.c misc.c spawn.c
-pmt_ehd_LDADD		= libcryptmount.la ${libHX_LIBS}
+pmt_ehd_LDADD		= libcryptmount.la ${libHX_LIBS} ${libcryptsetup_LIBS}
+endif
 
 pmt_fd0ssh_SOURCES	= fd0ssh.c
 
