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/gpt/gpt.go b/osbase/gpt/gpt.go
index 1c66816..126021b 100644
--- a/osbase/gpt/gpt.go
+++ b/osbase/gpt/gpt.go
@@ -227,7 +227,7 @@
 
 	fs, _, err := gpt.GetFreeSpaces()
 	if err != nil {
-		return fmt.Errorf("unable to determine free space: %v", err)
+		return fmt.Errorf("unable to determine free space: %w", err)
 	}
 	if opts.preferEnd {
 		// Reverse fs slice to start iteration at the end
@@ -530,7 +530,7 @@
 		hdrRaw.WriteByte(0x00)
 	}
 	if _, err := gpt.b.WriteAt(hdrRaw.Bytes(), (blockCount-1)*blockSize); err != nil {
-		return fmt.Errorf("failed to write alternate header: %v", err)
+		return fmt.Errorf("failed to write alternate header: %w", err)
 	}
 
 	// Sync device after writing each GPT, to ensure there is at least one valid
@@ -640,7 +640,7 @@
 	if err != nil {
 		alternateGPT, err2 := readSingleGPT(r, r.BlockCount()-1)
 		if err2 != nil {
-			return nil, fmt.Errorf("failed to read both GPTs: primary GPT (%v), secondary GPT (%v)", err, err2)
+			return nil, fmt.Errorf("failed to read both GPTs: primary GPT (%w), secondary GPT (%w)", err, err2)
 		}
 		alternateGPT.BootCode = bootCode
 		return alternateGPT, nil