lib/genalloc.c: export symbol addr_in_gen_pool

We use addr_in_gen_pool() in a driver module.  So export it.

Link: http://lkml.kernel.org/r/20181224070622.22197-2-sjhuang@iluvatar.ai


Signed-off-by: Huang Shijie <sjhuang@iluvatar.ai>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Alexey Skidanov <alexey.skidanov@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>