Btrfs: compress_file_range remove dead variable num_bytes

Remove dead assigment of num_bytes.

Also as num_bytes only used in the will_compress block as copy of
total_in just replace that with total_in and drop num_bytes entirely.
Signed-off-by: NTimofey Titovets <nefelim4ag@gmail.com>
Reviewed-by: NNikolay Borisov <nborisov@suse.com>
Reviewed-by: NDavid Sterba <dsterba@suse.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>

fs/btrfs/inode.c

@@ -458,7 +458,6 @@ static noinline void compress_file_range(struct inode *inode,
 {
 	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
 	struct btrfs_root *root = BTRFS_I(inode)->root;
-	u64 num_bytes;
 	u64 blocksize = fs_info->sectorsize;
 	u64 actual_end;
 	u64 isize = i_size_read(inode);
@@ -508,8 +507,6 @@ static noinline void compress_file_range(struct inode *inode,
 
 	total_compressed = min_t(unsigned long, total_compressed,
 			BTRFS_MAX_UNCOMPRESSED);
-	num_bytes = ALIGN(end - start + 1, blocksize);
-	num_bytes = max(blocksize,  num_bytes);
 	total_in = 0;
 	ret = 0;
 
@@ -625,7 +622,6 @@ static noinline void compress_file_range(struct inode *inode,
 		 */
 		total_in = ALIGN(total_in, PAGE_SIZE);
 		if (total_compressed + blocksize <= total_in) {
-			num_bytes = total_in;
 			*num_added += 1;
 
 			/*
@@ -633,12 +629,12 @@ static noinline void compress_file_range(struct inode *inode,
 			 * allocation on disk for these compressed pages, and
 			 * will submit them to the elevator.
 			 */
-			add_async_extent(async_cow, start, num_bytes,
+			add_async_extent(async_cow, start, total_in,
 					total_compressed, pages, nr_pages,
 					compress_type);
 
-			if (start + num_bytes < end) {
-				start += num_bytes;
+			if (start + total_in < end) {
+				start += total_in;
 				pages = NULL;
 				cond_resched();
 				goto again;