docs: Clean up bare :: lines

Mauro's patch set introduced some bare :: lines; these can be represented
by a double colon at the end of the preceding text line.  The result looks
a little less weird and is less verbose.

Signed-off-by: Jonathan Corbet <corbet@lwn.net>
diff --git a/Documentation/Changes b/Documentation/Changes
index 754cd50..22797a1 100644
--- a/Documentation/Changes
+++ b/Documentation/Changes
@@ -212,9 +212,7 @@
 
 A driver has been added to allow updating of Intel IA32 microcode,
 accessible as a normal (misc) character device.  If you are not using
-udev you may need to:
-
-::
+udev you may need to::
 
   mkdir /dev/cpu
   mknod /dev/cpu/microcode c 10 184
@@ -260,9 +258,7 @@
 upgrade pppd to at least 2.4.0.
 
 If you are not using udev, you must have the device file /dev/ppp
-which can be made by:
-
-::
+which can be made by::
 
   mknod /dev/ppp c 108 0
 
@@ -294,9 +290,7 @@
 dependency on ``rmtab`` and means that the kernel only needs to know about
 currently active clients.
 
-To enable this new functionality, you need to:
-
-::
+To enable this new functionality, you need to::
 
   mount -t nfsd nfsd /proc/fs/nfsd