cmd/link: make -a output not crash

Fixes #12107.

Change-Id: I62f1b6ac9fb6f2cfa3472253dc1c6f7b7d2a6faf
Reviewed-on: https://go-review.googlesource.com/13448Reviewed-by: David Crawshaw <crawshaw@golang.org>

src/cmd/link/internal/ld/data.go

@@ -778,7 +778,6 @@ func Codeblk(addr int64, size int64) {
 	}
 
 	eaddr := addr + size
-	var n int64
 	var q []byte
 	for ; sym != nil; sym = sym.Next {
 		if !sym.Reachable {
@@ -797,20 +796,18 @@ func Codeblk(addr int64, size int64) {
 		}
 
 		fmt.Fprintf(&Bso, "%.6x\t%-20s\n", uint64(int64(addr)), sym.Name)
-		n = sym.Size
 		q = sym.P
 
-		for n >= 16 {
-			fmt.Fprintf(&Bso, "%.6x\t%-20.16I\n", uint64(addr), q)
+		for len(q) >= 16 {
+			fmt.Fprintf(&Bso, "%.6x\t% x\n", uint64(addr), q[:16])
 			addr += 16
 			q = q[16:]
-			n -= 16
 		}
 
-		if n > 0 {
-			fmt.Fprintf(&Bso, "%.6x\t%-20.*I\n", uint64(addr), int(n), q)
+		if len(q) > 0 {
+			fmt.Fprintf(&Bso, "%.6x\t% x\n", uint64(addr), q)
+			addr += int64(len(q))
 		}
-		addr += n
 	}
 
 	if addr < eaddr {