docs: dm-crypt: Removal of unexpected indentation error

Add the required indentation to fix this docs build error:

  Documentation/admin-guide/device-mapper/dm-crypt.rst:167: ERROR: Unexpected indentation.

Also split the documentation for read and write into separate blocks.

Signed-off-by: Shibu kumar shibukumar.bit@gmail.com
[jc: rewrote changelog]
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Link: https://lore.kernel.org/r/20240803183306.32425-1-shibukumar.bit@gmail.com

Documentation/admin-guide/device-mapper/dm-crypt.rst

@@ -162,13 +162,19 @@ iv_large_sectors
 
 
 Module parameters::
-max_read_size
-max_write_size
-   Maximum size of read or write requests. When a request larger than this size
-   is received, dm-crypt will split the request. The splitting improves
-   concurrency (the split requests could be encrypted in parallel by multiple
-   cores), but it also causes overhead. The user should tune these parameters to
-   fit the actual workload.
+   max_read_size
+      Maximum size of read requests. When a request larger than this size
+      is received, dm-crypt will split the request. The splitting improves
+      concurrency (the split requests could be encrypted in parallel by multiple
+      cores), but it also causes overhead. The user should tune this parameters to
+      fit the actual workload.
+
+   max_write_size
+      Maximum size of write requests. When a request larger than this size
+      is received, dm-crypt will split the request. The splitting improves
+      concurrency (the split requests could be encrypted in parallel by multiple
+      cores), but it also causes overhead. The user should tune this parameters to
+      fit the actual workload.
 
 
 Example scripts