package_ipk: restore cwd after packaging

opkg-build needs to be executed in the root of the package, so save and restore
the current directory so this task doesn't modify the state.

(From OE-Core rev: 43dac97f397143abf61fc1c105ea0e4f2fffb90b)

Signed-off-by: Ross Burton <ross.burton@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

meta/classes/package_ipk.bbclass

@@ -21,6 +21,8 @@ python do_package_ipk () {
     import textwrap
     import subprocess
 
+    oldcwd = os.getcwd()
+
     workdir = d.getVar('WORKDIR', True)
     outdir = d.getVar('PKGWRITEDIRIPK', True)
     tmpdir = d.getVar('TMPDIR', True)
@@ -254,6 +256,7 @@ python do_package_ipk () {
         cleanupcontrol(root)
         bb.utils.unlockfile(lf)
 
+    os.chdir(oldcwd)
 }
 # Otherwise allarch packages may change depending on override configuration
 do_package_ipk[vardepsexclude] = "OVERRIDES"