Modify the format

Signed-off-by: NFondMemoryVVV <mashuai53@huawei.com>

toolchain/libc-test/src/toolchaintest.cpp

@@ -30,6 +30,7 @@
 #include "gtest/gtest.h"
 #include "runtest.h"
 
+using handler_type = void (*) (int);
 using namespace std;
 using namespace testing::ext;
 using namespace testing;
@@ -68,12 +69,11 @@ static int runTests(const char *argvs)
     int timeoutsec = 5, timeout = 0;
     int status, pid;
     sigset_t set;
-    void (*retfunc)(int);
 
     sigemptyset(&set);
     sigaddset(&set, SIGCHLD);
     sigprocmask(SIG_BLOCK, &set, nullptr);
-    retfunc = signal(SIGCHLD, handler);
+    handler_type retfunc = signal(SIGCHLD, handler);
     if (retfunc == SIG_ERR) {
         printf("signal triggering failed:%s\n", strerror(errno));
     }