nvme: make NVME_RDMA depend on BLOCK

Commit aa71987 ("nvme: fabrics drivers don't need the nvme-pci
driver") removed the dependency on BLK_DEV_NVME, but the cdoe does
depend on the block layer (which used to be an implicit dependency
through BLK_DEV_NVME).

Otherwise you get various errors from the kbuild test robot random
config testing when that happens to hit a configuration with BLOCK
device support disabled.

Cc: Christoph Hellwig <hch@lst.de>
Cc: Jay Freyensee <james_p_freyensee@linux.intel.com>
Cc: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/nvme/host/Kconfig

@@ -30,7 +30,7 @@ config NVME_FABRICS
 
 config NVME_RDMA
  tristate "NVM Express over Fabrics RDMA host driver"
- depends on INFINIBAND
+ depends on INFINIBAND && BLOCK
  select NVME_CORE
  select NVME_FABRICS
  select SG_POOL