[NFC] polish colossalai/kernel/cuda_native/csrc/kernels/include/dropout.h code style (#970)

colossalai/kernel/cuda_native/csrc/kernels/include/dropout.h

@@ -3,11 +3,13 @@
 #include <cuda.h>
 #include <cuda_fp16.h>
 #include <stdio.h>
+
 #include <string>
 
 #include "kernels.h"
 
-template <typename T> class Dropout {
+template <typename T>
+class Dropout {
  public:
   struct Config {
     float ratio;