[oe] Canadian Cross building broken due to PN in pkginfo files

[David Huggins-Daines]

This issue:

http://thread.gmane.org/gmane.comp.handhelds.openembedded/22376/focus=22556

also seems to affect building gcc-canadian-sdk - it leads to a "lockfile
path does not exist!" error where it's trying to create a lockfile in
the work directory for gcc-4.2.4-r3.

The problem happens here, in read_subpackage_metadata():

        for pkg in bb.data.getVar('PACKAGES', d, 1).split():
                sdata = read_subpkgdata(pkg, d)
                for key in sdata.keys():
                        bb.data.setVar(key, sdata[key], d)

The problem is that ${PN} is defined in the subpackage's pkginfo file,
so it overwrites the definition from the main package.  The last
subpackage defines PN="gcc", so that's where the packaging stage tries
to put the lockfile.

The original fix suggested in that thread seems to work well:

git revert -n 1af5030de05a1e65d1de734f7675ffc22c8318fc


I'm not sure what other packages or tasks this change might be affecting.