[MTD] mtdoops.c: make struct oops_cxt static again

struct oops_cxt needlessly became global.
Signed-off-by: Adrian Bunk <bunk@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>

drivers/mtd/mtdoops.c

@@ -35,7 +35,7 @@
 
 #define OOPS_PAGE_SIZE 4096
 
-struct mtdoops_context {
+static struct mtdoops_context {
 	int mtd_index;
 	struct work_struct work_erase;
 	struct work_struct work_write;