drivers/firmware/memmap.c: modify memblock_alloc to memblock_alloc_nopanic

drivers/firmware/memmap.c: modify memblock_alloc to memblock_alloc_nopanic

memblock_alloc() never returns NULL because panic never returns.

Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: huang.zijiang <[email protected]>
Acked-by: Mike Rapoport <[email protected]>
Cc: Michal Hocko <[email protected]>
Cc: Stephen Rothwell <[email protected]>
Cc: Michael Ellerman <[email protected]>
Cc: Yi Wang <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>