wimax/i2400m: fix spelling mistake "not unitialized" -> "uninitialized"

Trivial fix to spelling mistake in ms_to_errno array of error messages
and remove confusing "not" from the error text since the error code
refers to an uninitialized error code.

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: David S. Miller <davem@davemloft.net>