kernel/linux: fix using custom location

Currently, extract and patch are skipped as thus:
- using a custom directory of pre-installed headers
- a correctly named directory already exists

Otherwise, extract and patch are done.

The current second condition is wrong, because it allows the following
sequence to happen:
- a non-custom kernel is used
- a previous build only partially extracted the non-custom sources
- that p[revious build broke during extraction (eg. incomplete tarball...)
- a subsequent build will find a properly named directory, and will
thus skip extract and patch, which is wrong

Fix that by following the conditions in this table:

Type | Extract | Patch
----------------------+---------+-------
Pre-installed headers | N | N
custom directory | N | N
custom tarball | Y | N
mainstream tarball | Y | Y

Signed-off-by: "Yann E. MORIN" <yann.morin.1998@free.fr>
Cc: David Holsgrove <david.holsgrove@xilinx.com>

 From 47e88c04e01299f975ff23f33035d0f34a8f6787 Mon Sep 17 00:00:00 2001

 From: Bernhard Reutner-Fischer <rep.dot.nop@gmail.com>

 Date: Fri, 22 Jan 2010 13:32:44 +0100

 Subject: [PATCH 06/15] {,host}utils depend on headers

 Signed-off-by: Bernhard Reutner-Fischer <rep.dot.nop@gmail.com>

 ---

  Makefile.in |    4 ++--

  1 files changed, 2 insertions(+), 2 deletions(-)

 diff --git a/Makefile.in b/Makefile.in

 index 4c5aecb..ec4c28e 100644

 --- a/Makefile.in

 +++ b/Makefile.in

 @@ -436,7 +436,7 @@ ifeq ($(HAVE_SHARED),y)

  	fi

  endif

 -utils:

 +utils: headers

  	$(Q)$(MAKE) CROSS="$(CROSS)" CC="$(CC)" -C utils $@

  # Installs helper applications, such as 'ldd' and 'ldconfig'

 @@ -445,7 +445,7 @@ install_utils: utils

  endif # ifeq ($(HAVE_DOT_CONFIG),y)

 -hostutils:

 +hostutils: headers

  	$(Q)$(MAKE) CROSS="$(CROSS)" CC="$(CC)" HOSTCC="$(HOSTCC)" DOTHOST=.host -C utils $@

  install_hostutils: hostutils

 -- 

 1.6.6.1