nodejs: export DESTDIR to fix build with dash

* when building on machine with /bin/sh -> /bin/dash
  DESTDIR is empty in install and it's trying to write to /usr/include and fails

Signed-off-by: Martin Jansa <Martin.Jansa@gmail.com>

meta-oe/recipes-devtools/nodejs/nodejs_0.6.21.bb

@@ -54,7 +54,8 @@ do_compile () {
 }
 
 do_install () {
-  DESTDIR=${D} oe_runmake install
+  export DESTDIR=${D} 
+  oe_runmake install
 }
 
 RDEPENDS_${PN} = "curl python-shell python-datetime python-subprocess python-crypt python-textutils python-netclient "