hw/block/nvme: fix potential compilation error
assert may be compiled to a noop and we could end up returning an
uninitialized status.
Fix this by always returning Internal Device Error as a fallback.
Note that, as pointed out by Philippe, per commit
262a69f4282 ("osdep.h:
Prohibit disabling assert() in supported builds") this shouldn't be
possible. But clean it up so we don't worry about it again.
Signed-off-by: Gollu Appalanaidu <anaidu.gollu@samsung.com>
[k.jensen: split commit]
Signed-off-by: Klaus Jensen <k.jensen@samsung.com>