Fix typo in comments

csrc/flash_attn/src/fmha_bwd_hdim128.cu

 // Copyright (c) 2022, Tri Dao.
 
-// Splitting the different head dimentions to different files to speed up compilation.
+// Splitting the different head dimensions to different files to speed up compilation.
 
 #include "fmha_bwd_launch_template.h"
 

csrc/flash_attn/src/fmha_bwd_hdim32.cu

 // Copyright (c) 2022, Tri Dao.
 
-// Splitting the different head dimentions to different files to speed up compilation.
+// Splitting the different head dimensions to different files to speed up compilation.
 
 #include "fmha_bwd_launch_template.h"
 

csrc/flash_attn/src/fmha_bwd_hdim64.cu

 // Copyright (c) 2022, Tri Dao.
 
-// Splitting the different head dimentions to different files to speed up compilation.
+// Splitting the different head dimensions to different files to speed up compilation.
 
 #include "fmha_bwd_launch_template.h"
 

csrc/flash_attn/src/fmha_fwd_hdim128.cu

 // Copyright (c) 2022, Tri Dao.
 
-// Splitting the different head dimentions to different files to speed up compilation.
+// Splitting the different head dimensions to different files to speed up compilation.
 
 #include "fmha_fwd_launch_template.h"
 

csrc/flash_attn/src/fmha_fwd_hdim32.cu

 // Copyright (c) 2022, Tri Dao.
 
-// Splitting the different head dimentions to different files to speed up compilation.
+// Splitting the different head dimensions to different files to speed up compilation.
 
 #include "fmha_fwd_launch_template.h"
 

csrc/flash_attn/src/fmha_fwd_hdim64.cu

 // Copyright (c) 2022, Tri Dao.
 
-// Splitting the different head dimentions to different files to speed up compilation.
+// Splitting the different head dimensions to different files to speed up compilation.
 
 #include "fmha_fwd_launch_template.h"