fix code style

Signed-off-by: Nzhong_ning <zhong_ning@hoperun.com>

services/test/unittest/common/cmd_func_test.cpp

@@ -522,7 +522,7 @@ static char* ReadFileToBuf()
             break;
         }
 
-        buffer = static_cast<char*>malloc((size_t)fileStat.st_size + 1);
+        buffer = static_cast<char*>(malloc((size_t)fileStat.st_size + 1));
         if (buffer == nullptr) {
             break;
         }