mtd: map: BUG() in non handled cases

Several map-related functions look like a serie of ifs, checking
widths of map. Those functions do not have any handling for default
case. Instead of fiddling with uninitialized_var in those functions,
let's just add a (correct) BUG() to the default case on those maps. This
will also allow us to catch potential errors in maps setup in future.

Signed-off-by: Dmitry Eremin-Solenikov <[e-mail]>
Signed-off-by: Artem Bityutskiy <[e-mail]>

include/linux/mtd/map.h

···
 
 static inline map_word map_word_load(struct map_info *map, const void *ptr)
 {
-	map_word r = {{0} };
+	map_word r;
 
 	if (map_bankwidth_is_1(map))
 		r.x[0] = *(unsigned char *)ptr;
···
 #endif
 	else if (map_bankwidth_is_large(map))
 		memcpy(r.x, ptr, map->bankwidth);
+	else
+		BUG();
 
 	return r;
 }
···
 
 static inline map_word inline_map_read(struct map_info *map, unsigned long ofs)
 {
-	map_word uninitialized_var(r);
+	map_word r;
 
 	if (map_bankwidth_is_1(map))
 		r.x[0] = __raw_readb(map->virt + ofs);
···
 #endif
 	else if (map_bankwidth_is_large(map))
 		memcpy_toio(map->virt+ofs, datum.x, map->bankwidth);
+	else
+		BUG();
 	mb();
 }