qemuMigrationCookieXMLParse: Remove comment mentioning that error was already set
qemuMigrationCookieXMLParse: Remove comment mentioning that error was already set

Most of our functions report errors so there's no need to mention it
here again.

Signed-off-by: Peter Krempa <2cf5c04c61aa466e4a47bfedc747d17279c72ffc@redhat.com>
Reviewed-by: Michal Privoznik <83d82aaba2eed257f4814b0c239c260c4caaadf0@redhat.com>

crobinso/libvirt,libvirt/libvirt,libvirt/libvirt,jfehlig/libvirt,olafhering/libvirt,crobinso/libvirt,jfehlig/libvirt,olafhering/libvirt,nertpinx/libvirt,nertpinx/libvirt,olafhering/libvirt,libvirt/libvirt,jardasgit/libvirt,zippy2/libvirt,jardasgit/libvirt,olafhering/libvirt,zippy2/libvirt,crobinso/libvirt,zippy2/libvirt,nertpinx/libvirt,nertpinx/libvirt,crobinso/libvirt,libvirt/libvirt,jfehlig/libvirt,jardasgit/libvirt,jardasgit/libvirt,nertpinx/libvirt,jfehlig/libvirt,zippy2/libvirt,jardasgit/libvirt