Correct path in DOS handbook example.

PR:         253560
Patch by:   ceri (AT) submonkey.net

documentation/content/en/books/handbook/preface/_index.adoc

@@ -221,7 +221,7 @@ Examples starting with [.filename]#C:\># indicate a MS-DOS(R) command. Unless ot
 
 [source,bash]
 ....
-E:\> tools\fdimage floppies\kern.flp A:
+C:\> tools\fdimage floppies\kern.flp A:
 ....
 
 Examples starting with # indicate a command that must be invoked as the superuser in FreeBSD. You can login as `root` to type the command, or login as your normal account and use man:su[1] to gain superuser privileges.