CPack/DEB: rename variable w/ result of dpkg find to match other vars

Modules/Internal/CPack/CPackDeb.cmake

@@ -612,13 +612,13 @@ function(cpack_deb_prepare_package_vars)
   elseif(NOT CPACK_DEBIAN_PACKAGE_ARCHITECTURE)
     # There is no such thing as i686 architecture on debian, you should use i386 instead
     # $ dpkg --print-architecture
-    find_program(DPKG_CMD dpkg)
-    if(NOT DPKG_CMD)
+    find_program(DPKG_EXECUTABLE dpkg)
+    if(NOT DPKG_EXECUTABLE)
       message(STATUS "CPackDeb: Can not find dpkg in your path, default to i386.")
       set(CPACK_DEBIAN_PACKAGE_ARCHITECTURE i386)
     endif()
     execute_process(
-      COMMAND "${DPKG_CMD}" --print-architecture
+      COMMAND "${DPKG_EXECUTABLE}" --print-architecture
       OUTPUT_VARIABLE CPACK_DEBIAN_PACKAGE_ARCHITECTURE
       OUTPUT_STRIP_TRAILING_WHITESPACE
     )