deviceinfo: replace implementation with mvdan/sh (MR 52)

This library has a convenient "source file" method designed for sourcing
shell envs and returning values set in them. deviceinfo's syntax every
where else seems to be "whatever sh can 'source'", so using this library
seems a lot nicer than trying to implement a parser/interpreter here
(and almost certainly missing corner cases, functionality, etc)

[ci:skip-build]: already built successfully in CI

pkgs/deviceinfo/deviceinfo_test.go

@@ -4,8 +4,6 @@
 package deviceinfo
 
 import (
-	"fmt"
-	"reflect"
 	"strings"
 	"testing"
 )
@@ -59,37 +57,24 @@ func TestUnmarshal(t *testing.T) {
 	tables := []struct {
 		// field is just used for reflection within the test, so it must be a
 		// valid DeviceInfo field
-		field    string
-		in       string
-		expected string
+		file     string
+		expected DeviceInfo
 	}{
-		{"InitfsCompression", "deviceinfo_initfs_compression=\"gzip:-9\"\n", "gzip:-9"},
-		// line with multiple '='
-		{"InitfsCompression", "deviceinfo_initfs_compression=zstd:--foo=1 -T0 --bar=bazz", "zstd:--foo=1 -T0 --bar=bazz"},
-		// empty option
-		{"InitfsCompression", "deviceinfo_initfs_compression=\"\"\n", ""},
-		// line with comment at the end
-		{"", "# this is a comment!\n", ""},
-		// empty lines are fine
-		{"", "", ""},
-		// line with whitepace characters only
-		{"", " \t \n\r", ""},
+		{"./test_resources/deviceinfo-unmarshal-1", DeviceInfo{
+			FormatVersion:          "0",
+			UbootBoardname:         "foobar-bazz",
+			InitfsCompression:      "zstd:--foo=1 -T0 --bar=bazz",
+			InitfsExtraCompression: "",
+		},
+		},
 	}
 	var d DeviceInfo
 	for _, table := range tables {
-		testName := fmt.Sprintf("unmarshal::'%s':", strings.ReplaceAll(table.in, "\n", "\\n"))
-		if err := d.unmarshal(strings.NewReader(table.in)); err != nil {
-			t.Errorf("%s received an unexpected err: ", err)
+		if err := d.unmarshal(table.file); err != nil {
+			t.Error(err)
 		}
-
-		// Check against expected value
-		field := reflect.ValueOf(&d).Elem().FieldByName(table.field)
-		out := ""
-		if table.field != "" {
-			out = field.String()
-		}
-		if out != table.expected {
-			t.Errorf("%s expected: %q, got: %q", testName, table.expected, out)
+		if d != table.expected {
+			t.Errorf("expected: %s, got: %s", table.expected, d)
 		}
 	}