docs: Fix some formatting issues in request-key.rst

The white space in the big enumerated list was inconsistent, leading to
some strange formatting artifacts.
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

Documentation/security/keys/request-key.rst

@@ -105,7 +105,7 @@ A request proceeds in the following manner:
      UID, GID, groups and security info of process A as if it was process A,
      and come up with key W.
 
- (8) The program then does what it must to get the data with which to
+  8) The program then does what it must to get the data with which to
      instantiate key U, using key W as a reference (perhaps it contacts a
      Kerberos server using the TGT) and then instantiates key U.