NVMe: Detect command IDs completing that are out of range

NVMe: Detect command IDs completing that are out of range

If the adapter completes a command ID that is outside the bounds of
the array, return CMD_CTX_INVALID instead of random data, and print a
message in the sync_completion handler (which is rapidly becoming the
misc completion handler :-)

Signed-off-by: Matthew Wilcox <matthew.r.wilcox@intel.com>