treewide: fix %v in cases where we should use %w

We should always use %w when using fmt.Errorf as you can use error.Is to
compare the underlying error. When printing an error the use of %w is
wrong and should be replaced with %v.

Change-Id: I741111bd91dcee4099144d2ecaffa879fdbb34a2
Reviewed-on: https://review.monogon.dev/c/monogon/+/2993
Tested-by: Jenkins CI
Reviewed-by: Lorenz Brun <lorenz@monogon.tech>
diff --git a/osbase/fat32/fat32.go b/osbase/fat32/fat32.go
index a0b8414..e0d460f 100644
--- a/osbase/fat32/fat32.go
+++ b/osbase/fat32/fat32.go
@@ -397,7 +397,7 @@
 
 	for _, i := range p.orderedInodes {
 		if err := i.writeData(wb, bs.Label); err != nil {
-			return fmt.Errorf("failed to write inode %q: %v", i.Name, err)
+			return fmt.Errorf("failed to write inode %q: %w", i.Name, err)
 		}
 		if err := wb.FinishBlock(int64(opts.BlockSize)*int64(bs.BlocksPerCluster), false); err != nil {
 			return err
@@ -423,7 +423,7 @@
 	if opts.ID == 0 {
 		var buf [4]byte
 		if _, err := rand.Read(buf[:]); err != nil {
-			return nil, nil, nil, fmt.Errorf("failed to assign random FAT ID: %v", err)
+			return nil, nil, nil, fmt.Errorf("failed to assign random FAT ID: %w", err)
 		}
 		opts.ID = binary.BigEndian.Uint32(buf[:])
 	}