parport_pc: fix find_superio io compare code, should use equal test.

BugLink: https://bugs.launchpad.net/bugs/1822271

commit 21698fd5 upstream.

In the original code before 181bf1e8 the loop was continuing until
it finds the first matching superios[i].io and p->base.
But after 181bf1e8 the logic changed and the loop now returns the
pointer to the first mismatched array element which is then used in
get_superio_dma() and get_superio_irq() and thus returning the wrong
value.
Fix the condition so that it now returns the correct pointer.

Fixes: 181bf1e8 ("parport_pc: clean up the modified while loops using for")
Cc: Alan Cox <alan@linux.intel.com>
Cc: stable@vger.kernel.org
Signed-off-by: QiaoChong <qiaochong@loongson.cn>
[rewrite the commit message]
Signed-off-by: Sudip Mukherjee <sudipm.mukherjee@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>
Acked-by: Juerg Haefliger <juerg.haefliger@canonical.com>
Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>

drivers/parport/parport_pc.c

@@ -1377,7 +1377,7 @@ static struct superio_struct *find_superio(struct parport *p)
 {
 	int i;
 	for (i = 0; i < NR_SUPERIOS; i++)
-		if (superios[i].io != p->base)
+		if (superios[i].io == p->base)
 			return &superios[i];
 	return NULL;
 }