tests: make CI happy

Author: zhouwg

tests/simple-backend-ut.cpp

@@ -24,18 +24,9 @@
 #include <stdint.h>
 #include <string.h>
 #include <stddef.h>
-#include <unistd.h>
 #include <inttypes.h>
 #include <math.h>
 #include <time.h>
-#include <unistd.h>
-#include <dlfcn.h>
-#include <fcntl.h>
-#include <sys/stat.h>
-#include <limits.h>
-#include <signal.h>
-#include <fcntl.h>
-#include <sys/types.h>
 
 #include <string>
 #include <vector>