*: reflow comments to 80 characters

This reformats the entire Metropolis codebase to have comments no longer
than 80 characters, implementing CR/66.

This has been done half manually, as we don't have a good integration
between commentwrap/Bazel, but that can be implemented if we decide to
go for this tool/limit.

Change-Id: If1fff0b093ef806f5dc00551c11506e8290379d0
diff --git a/metropolis/pkg/erofs/defs.go b/metropolis/pkg/erofs/defs.go
index b547867..85898bf 100644
--- a/metropolis/pkg/erofs/defs.go
+++ b/metropolis/pkg/erofs/defs.go
@@ -16,11 +16,13 @@
 
 package erofs
 
-// This file contains definitions coming from the in-Kernel implementation of the EROFS filesystem.
-// All definitions come from @linux//fs/erofs:erofs_fs.h unless stated otherwise.
+// This file contains definitions coming from the in-Kernel implementation of
+// the EROFS filesystem.  All definitions come from @linux//fs/erofs:erofs_fs.h
+// unless stated otherwise.
 
-// Magic contains the 4 magic bytes starting at position 1024 identifying an EROFS filesystem.
-// Defined in @linux//include/uapi/linux/magic.h EROFS_SUPER_MAGIC_V1
+// Magic contains the 4 magic bytes starting at position 1024 identifying an
+// EROFS filesystem.  Defined in @linux//include/uapi/linux/magic.h
+// EROFS_SUPER_MAGIC_V1
 var Magic = [4]byte{0xe2, 0xe1, 0xf5, 0xe0}
 
 const blockSizeBits = 12