mtd: make few symbols static

Make mtd_group and mtd_groups static since they are only used in this
file.

[Amended by Artem Bityutskiy]

Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
diff --git a/drivers/mtd/mtdcore.c b/drivers/mtd/mtdcore.c
index 00ebf7a..3f559c0 100644
--- a/drivers/mtd/mtdcore.c
+++ b/drivers/mtd/mtdcore.c
@@ -213,11 +213,11 @@
 	NULL,
 };
 
-struct attribute_group mtd_group = {
+static struct attribute_group mtd_group = {
 	.attrs		= mtd_attrs,
 };
 
-struct attribute_group *mtd_groups[] = {
+static struct attribute_group *mtd_groups[] = {
 	&mtd_group,
 	NULL,
 };