all: Don't use portVersionedName for SOURCE_DIR

* portVersionedName contains the secondary architecture,
  so using it means secondary package builds fail.
  example: $portVersionedName is libwow_x86-0.0.0 when
  doing an x86 build on x86_gcc2

dev-python/docutils/docutils-0.11.recipe

@@ -17,7 +17,6 @@ LICENSE="Public Domain
 	Python"
 REVISION="1"
 ARCHITECTURES="x86 x86_gcc2"
-SOURCE_DIR="$portVersionedName"
 
 PROVIDES="
 	docutils = $portVersion

dev-python/dulwich/dulwich-0.9.1.recipe

@@ -34,7 +34,6 @@ BUILD_PREREQUIRES="
 	cmd:gcc
 	"
 
-SOURCE_DIR="$portVersionedName"
 
 BUILD()
 {

dev-python/ordereddict/ordereddict-1.1.recipe

@@ -13,7 +13,6 @@ LICENSE="MIT"
 REVISION="1"
 ARCHITECTURES="x86 x86_gcc2"
 
-SOURCE_DIR="$portVersionedName"
 
 PROVIDES="
 	ordereddict = $portVersion