Use CMAKE_COMMAND variable instead of plain cmake executable

CMakeLists.txt

@@ -208,7 +208,7 @@ if(ZLIB_TEST AND NOT CMAKE_CROSSCOMPILING)
                 GENERATE OUTPUT ${CMAKE_CURRENT_BINARY_DIR}/$<CONFIG>/test_${target}.cmake
                 CONTENT
                 "execute_process(
-                    COMMAND cmake -E echo hello world
+                    COMMAND \${CMAKE_COMMAND} -E echo hello world
                     COMMAND $<TARGET_FILE:${target}>
                     COMMAND $<TARGET_FILE:${target}> -d
                     COMMAND_ERROR_IS_FATAL ANY