vt_fb_attach() currently always returns 0, but it could return a code
defined in errno.h. However, it doesn't return a CN_* code. So checking
its return value against CN_DEAD (which is 0) is incorrect, and in this
case, a success becomes a failure.
The consequence was unimportant, because the caller (drm_fb_helper.c)
would only log an error message in this case. The console would still
work.
Approved by: nwhitehorn
49b200df0d