btrfs: compression: Add linux/sizes.h for compression.h

Since compression.h is using the SZ_* macros, and if some file includes
only compression.h without linux/sizes.h, it will cause compile error.

One example is lzo.c, if it uses BTRFS_MAX_COMPRESSED.  Fix it by adding
linux/sizes.h in compression.h

Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

fs/btrfs/compression.h

@@ -6,6 +6,8 @@
 #ifndef BTRFS_COMPRESSION_H
 #define BTRFS_COMPRESSION_H
 
+#include <linux/sizes.h>
+
 /*
  * We want to make sure that amount of RAM required to uncompress an extent is
  * reasonable, so we limit the total size in ram of a compressed extent to