[MTD] [NAND] fix broken debug messages

Fix incorrect debug messages (*write* not read); someone committed some
cut'n'paste bugs.   There might be more, I only noticed these since I was
looking for nand_read usage and landed in some very wrong functions.

IMO all MTD debugging message framework is goofed, anyway.  It uses
"DEBUG" in a way that's incompatible with usage most everywhere else in
the kernel, and which prevents normal pr_dbg() and dev_dbg() calls from
working right.

[True. It predates those by a long way, and should probably be updated 
to use them. dwmw2]

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>