docbook: skip files with no docs since they generate scary warnings

Fix docbook templates that reference files that do not contain the
expected kernel-doc notation.

Fixes these warnings:

Warning(arch/x86/include/asm/unaligned.h): no structured comments found
Warning(lib/vsprintf.c): no structured comments found

These cause errors in the generated html output, like below, so drop
these lines.

Name
arch/x86/include/asm/unaligned.h - Document generation inconsistency
Oops
Warning
The template for this document tried to insert the structured comment from the file arch/x86/include/asm/unaligned.h at this point, but none was found. This dummy section is inserted to allow generation to continue.

Signed-off-by: Randy Dunlap <[e-mail]>
Signed-off-by: Linus Torvalds <[e-mail]>

Documentation/DocBook/device-drivers.tmpl

···
 
      <sect1><title>Atomic and pointer manipulation</title>
 !Iarch/x86/include/asm/atomic.h
-!Iarch/x86/include/asm/unaligned.h
      </sect1>
 
      <sect1><title>Delaying, scheduling, and timer routines</title>

Documentation/DocBook/kernel-api.tmpl

···
      </para>
 
      <sect1><title>String Conversions</title>
-!Ilib/vsprintf.c
 !Elib/vsprintf.c
      </sect1>
      <sect1><title>String Manipulation</title>