i810fb: fix console switch regression

Since 4c7ffe0b ("fbdev: prevent drivers that
have hardware cursors from calling software cursor code") every call of
i810fb_cursor fails with -ENXIO because of a incorrect "!".

This hasn't struck until eaa0ff15 ("fix !
versus & precedence in various places") surrounded the expression with braces,
so that the intended behavior was inverted.  That caused 'pixel waste' - the
same line of multi-colored pixels repeated over the whole screen - during
console switch.

This switches back to the original pre-4c7ffe0b

 behavior.

Signed-off-by: Stefan Bauer <stefan.bauer@cs.tu-chemnitz.de>
Tested-by: Stefan Bauer <stefan.bauer@cs.tu-chemnitz.de>
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Antonino Daplas <adaplas@pol.net>
Cc: Henrique de Moraes Holschuh <hmh@hmh.eng.br>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>