Fix error message grammar

builder/azure/chroot/step_verify_shared_image_destination.go

@@ -99,7 +99,7 @@ func (s *StepVerifySharedImageDestination) Run(ctx context.Context, state multis
 			return errorMessage("Could not retrieve versions for image %q: unexpected nil name", to.String(image.ID))
 		}
 		if *version.Name == s.Image.ImageVersion {
-			return errorMessage("Shared image version %q already exists from image %q.", s.Image.ImageVersion, to.String(image.ID))
+			return errorMessage("Shared image version %q already exists for image %q.", s.Image.ImageVersion, to.String(image.ID))
 		}
 
 		err := versions.NextWithContext(ctx)

builder/azure/chroot/step_verify_shared_image_destination_test.go

@@ -71,7 +71,7 @@ func TestStepVerifySharedImageDestination_Run(t *testing.T) {
 		{
 			name:    "version exists",
 			want:    multistep.ActionHalt,
-			wantErr: "Shared image version \"2.3.4\" already exists from image \"image-resourceid-goes-here\".",
+			wantErr: "Shared image version \"2.3.4\" already exists for image \"image-resourceid-goes-here\".",
 			fields: fields{
 				Image: SharedImageGalleryDestination{
 					ResourceGroup: "rg",