Use actual executable name

CMakeLists.txt

 find_program(BASE64 base64 DOC "path to base64 executable")
 
 add_executable(${PROJECT_NAME} postsrsd.c sha1.c srs2.c)
+
+get_target_property(POSTSRSD ${PROJECT_NAME} LOCATION)
+get_filename_component(POSTSRSD ${POSTSRSD} NAME_WE)
+
 configure_file(${PROJECT_NAME}.init.in ${PROJECT_NAME}.init @ONLY)
 configure_file(postinstall.cmake.in postinstall.cmake @ONLY)
 

postsrsd.init.in

 set -e
 
 PATH=/sbin:/bin:/usr/sbin:/usr/bin
-DAEMON=@CMAKE_INSTALL_PREFIX@/sbin/@PROJECT_NAME@
+DAEMON=@CMAKE_INSTALL_PREFIX@/sbin/@POSTSRSD@
 NAME=@PROJECT_NAME@
 DESC="Postfix Sender Rewriting Scheme daemon"