mi: Hush extension initialization (#75870)

Printing these as ErrorF is fairly obnoxious, since it means the
non-hardware servers now spew stuff to the console for entirely routine
events.  And actually, printing these at all is fairly obnoxious, since
a) we're printing a line for every extension, whether it's enabled or
not, and b) we're not actually initializing the extension at this point.

Signed-off-by: Adam Jackson <ajax@redhat.com>
Reviewed-by: Daniel Stone <daniel@fooishbar.org>
Signed-off-by: Keith Packard <keithp@keithp.com>