docbook: change iomap source filename in deviceiobook

Fix warning since kernel-doc comments were moved to another
source file.

Warning(lib/iomap.c): no structured comments found

Signed-off-by: Randy Dunlap <rdunlap@xenotime.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/Documentation/DocBook/deviceiobook.tmpl b/Documentation/DocBook/deviceiobook.tmpl
index c1ed6a4..54199a0 100644
--- a/Documentation/DocBook/deviceiobook.tmpl
+++ b/Documentation/DocBook/deviceiobook.tmpl
@@ -317,7 +317,7 @@
   <chapter id="pubfunctions">
      <title>Public Functions Provided</title>
 !Iarch/x86/include/asm/io.h
-!Elib/iomap.c
+!Elib/pci_iomap.c
   </chapter>
 
 </book>