btrfs: cleanup, rename a few variables in btrfs_read_sys_array

There's a pointer to buffer, integer offset and offset passed as
pointer, try to find matching names for them.
Signed-off-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <clm@fb.com>

fs/btrfs/volumes.c

@@ -6252,13 +6252,13 @@ int btrfs_read_sys_array(struct btrfs_root *root)
 	struct extent_buffer *sb;
 	struct btrfs_disk_key *disk_key;
 	struct btrfs_chunk *chunk;
-	u8 *ptr;
-	unsigned long sb_ptr;
+	u8 *array_ptr;
+	unsigned long sb_array_offset;
 	int ret = 0;
 	u32 num_stripes;
 	u32 array_size;
 	u32 len = 0;
-	u32 cur;
+	u32 cur_offset;
 	struct btrfs_key key;
 
 	ASSERT(BTRFS_SUPER_INFO_SIZE <= root->nodesize);
@@ -6290,20 +6290,21 @@ int btrfs_read_sys_array(struct btrfs_root *root)
 	write_extent_buffer(sb, super_copy, 0, BTRFS_SUPER_INFO_SIZE);
 	array_size = btrfs_super_sys_array_size(super_copy);
 
-	ptr = super_copy->sys_chunk_array;
-	sb_ptr = offsetof(struct btrfs_super_block, sys_chunk_array);
-	cur = 0;
+	array_ptr = super_copy->sys_chunk_array;
+	sb_array_offset = offsetof(struct btrfs_super_block, sys_chunk_array);
+	cur_offset = 0;
 
-	while (cur < array_size) {
-		disk_key = (struct btrfs_disk_key *)ptr;
+	while (cur_offset < array_size) {
+		disk_key = (struct btrfs_disk_key *)array_ptr;
 		btrfs_disk_key_to_cpu(&key, disk_key);
 
-		len = sizeof(*disk_key); ptr += len;
-		sb_ptr += len;
-		cur += len;
+		len = sizeof(*disk_key);
+		array_ptr += len;
+		sb_array_offset += len;
+		cur_offset += len;
 
 		if (key.type == BTRFS_CHUNK_ITEM_KEY) {
-			chunk = (struct btrfs_chunk *)sb_ptr;
+			chunk = (struct btrfs_chunk *)sb_array_offset;
 			ret = read_one_chunk(root, &key, sb, chunk);
 			if (ret)
 				break;
@@ -6313,9 +6314,9 @@ int btrfs_read_sys_array(struct btrfs_root *root)
 			ret = -EIO;
 			break;
 		}
-		ptr += len;
-		sb_ptr += len;
-		cur += len;
+		array_ptr += len;
+		sb_array_offset += len;
+		cur_offset += len;
 	}
 	free_extent_buffer(sb);
 	return ret;