mtd: Disable mtdchar mmap on MMU systems

commit f5cf8f07 upstream.

This code was broken because it assumed that all MTD devices were map-based.
Disable it for now, until it can be fixed properly for the next merge window.
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

drivers/mtd/mtdchar.c

@@ -1154,7 +1154,11 @@ static int mtd_mmap(struct file *file, struct vm_area_struct *vma)
 	unsigned long off;
 	u32 len;
 
-	if (mtd->type == MTD_RAM || mtd->type == MTD_ROM) {
+        /* This is broken because it assumes the MTD device is map-based
+	   and that mtd->priv is a valid struct map_info.  It should be
+	   replaced with something that uses the mtd_get_unmapped_area()
+	   operation properly. */
+	if (0 /*mtd->type == MTD_RAM || mtd->type == MTD_ROM*/) {
 		off = vma->vm_pgoff << PAGE_SHIFT;
 		start = map->phys;
 		len = PAGE_ALIGN((start & ~PAGE_MASK) + map->size);