mxcmmc: fix error path in mxcmci_probe

After a failing allocation of mmc or a failed ioremap in mxcmci_probe host was
used uninitialized.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Acked-by: Sascha Hauer <s.hauer@pengutronix.de>
Cc: Pierre Ossman <pierre@ossman.eu>
Cc: Martin Fuzzey <mfuzzey@gmail.com>
Cc: Pierre Ossman <drzeus@drzeus.cx>
Cc: <linux-mmc@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>