Patches for -bk/-mm4.

Hi Andrew,
today I've 7 patches for you to consider. One is common code, 6 are s390 bug fixes. I've another one which adds experimental cpu hotplug support for s390 which works on the -bk tree but not one the -mm4 tree. I could track it down to two patches in -mm4, if I remove sched-cleanup-improve-sched-fork-apis.patch and sched-cleanup-init_idle.patch the hotplugging works on -mm4. I'll have to investigate further what's wrong here.

The common code problem is in lib/radix-tree.c where an int is shifted by more then 32 bits. We stumbled over this problem with the efi partition code. After a dasd device is freshly formatted it has 0 blocks. The efi partition code tries to load the last block of the device which turns out to number -1. A mapping for page at index (~0UL >> 3) related to a bdev inode is established. Due to the bug in the radix tree code the page isn't found when the bdev gets released and the nrpages counter stays 1 -> "kernel BUG() at fs/inode.c:238!".

Have fun & blue skies,
Martin.