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>

diff -durN binutils-2.20.1.orig/ld/emulparams/elf_i386.sh binutils-2.20.1/ld/emulparams/elf_i386.sh

--- binutils-2.20.1.orig/ld/emulparams/elf_i386.sh	2009-07-29 16:59:23.000000000 +0200

+++ binutils-2.20.1/ld/emulparams/elf_i386.sh	2010-08-17 19:32:12.000000000 +0200

@@ -13,3 +13,13 @@

 NO_SMALL_DATA=yes

 SEPARATE_GOTPLT=12

 IREL_IN_PLT=

+

+# In Gentoo, we install 32bit libs into /lib32 in an

+# ABI setup with amd64/x86

+case "$target" in

+  x86_64*-linux*)

+    case "$EMULATION_NAME" in

+      *i386*) LIBPATH_SUFFIX=32  ;;

+    esac

+  ;;

+esac