wg302v1_fixup() looks for the ATAG_CMDLINE atag, it doesn't find it and
so it takes the last atag in the list and overwrites non allocated
memory.
The side effects are corrupted vital data and a kernel that doesn't
boot. More details here https://dev.openwrt.org/ticket/18356
The fix appends the fixup to the command line and updates the atag only
when it finds it.
Signed-off-by: Gianluca Anzolin <gianluca@sottospazio.it>
SVN-Revision: 43320
