Create convert_fbe breadcrumb file to support conversion to FBE

Change-Id: I38b29e1e34ea793e4b87cd27a1d39fa905fddf7a
diff --git a/roots.cpp b/roots.cpp
index 12c6b5e..f361cb8 100644
--- a/roots.cpp
+++ b/roots.cpp
@@ -175,7 +175,7 @@
     return WEXITSTATUS(status);
 }
 
-int format_volume(const char* volume) {
+int format_volume(const char* volume, const char* directory) {
     Volume* v = volume_for_path(volume);
     if (v == NULL) {
         LOGE("unknown volume \"%s\"\n", volume);
@@ -241,7 +241,7 @@
         }
         int result;
         if (strcmp(v->fs_type, "ext4") == 0) {
-            result = make_ext4fs(v->blk_device, length, volume, sehandle);
+            result = make_ext4fs_directory(v->blk_device, length, volume, sehandle, directory);
         } else {   /* Has to be f2fs because we checked earlier. */
             if (v->key_loc != NULL && strcmp(v->key_loc, "footer") == 0 && length < 0) {
                 LOGE("format_volume: crypt footer + negative length (%zd) not supported on %s\n", length, v->fs_type);
@@ -273,6 +273,10 @@
     return -1;
 }
 
+int format_volume(const char* volume) {
+    return format_volume(volume, NULL);
+}
+
 int setup_install_mounts() {
     if (fstab == NULL) {
         LOGE("can't set up install mounts: no fstab loaded\n");