proc: remove docbook and example

Example is outdated, it still uses old ->read_proc interfaces and "fb"
example is plain racy.  There are better examples all over the tree.

Docbook itself says almost nothing about /proc and contain quite a number
of simply wrong facts, e.g.  device nodes support.  What it does is
describing at great length interface which are going to be removed.

There are Documentation/filesystems/seq_file.txt in exchange.

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Acked-by: Erik Mouw <mouw@nl.linux.org>
Cc: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/Documentation/DocBook/Makefile b/Documentation/DocBook/Makefile
index ab8300f..ee34ceb 100644
--- a/Documentation/DocBook/Makefile
+++ b/Documentation/DocBook/Makefile
@@ -8,7 +8,7 @@
 
 DOCBOOKS := z8530book.xml mcabook.xml device-drivers.xml \
 	    kernel-hacking.xml kernel-locking.xml deviceiobook.xml \
-	    procfs-guide.xml writing_usb_driver.xml networking.xml \
+	    writing_usb_driver.xml networking.xml \
 	    kernel-api.xml filesystems.xml lsm.xml usb.xml kgdb.xml \
 	    gadget.xml libata.xml mtdnand.xml librs.xml rapidio.xml \
 	    genericirq.xml s390-drivers.xml uio-howto.xml scsi.xml \
@@ -65,7 +65,7 @@
 DOCPROC   = $(objtree)/scripts/basic/docproc
 
 XMLTOFLAGS = -m $(srctree)/Documentation/DocBook/stylesheet.xsl
-#XMLTOFLAGS += --skip-validation
+XMLTOFLAGS += --skip-validation
 
 ###
 # DOCPROC is used for two purposes:
@@ -101,17 +101,6 @@
 # Changes in kernel-doc force a rebuild of all documentation
 $(BOOKS): $(KERNELDOC)
 
-###
-# procfs guide uses a .c file as example code.
-# This requires an explicit dependency
-C-procfs-example = procfs_example.xml
-C-procfs-example2 = $(addprefix $(obj)/,$(C-procfs-example))
-$(obj)/procfs-guide.xml: $(C-procfs-example2)
-
-# List of programs to build
-##oops, this is a kernel module::hostprogs-y := procfs_example
-obj-m += procfs_example.o
-
 # Tell kbuild to always build the programs
 always := $(hostprogs-y)
 
@@ -238,7 +227,7 @@
 	$(patsubst %.xml, %.pdf,  $(DOCBOOKS)) \
 	$(patsubst %.xml, %.html, $(DOCBOOKS)) \
 	$(patsubst %.xml, %.9,    $(DOCBOOKS)) \
-	$(C-procfs-example) $(index)
+	$(index)
 
 clean-dirs := $(patsubst %.xml,%,$(DOCBOOKS)) man