Unmount sdcard if no package file is selected.

Change-Id: I12b4f880802135a98dbc11a19e74172a3a5ef921
diff --git a/recovery.cpp b/recovery.cpp
index 76149cd..a7dc6ed 100644
--- a/recovery.cpp
+++ b/recovery.cpp
@@ -772,6 +772,7 @@
     char* path = browse_directory(SDCARD_ROOT, device);
     if (path == NULL) {
         ui->Print("\n-- No package file selected.\n");
+        ensure_path_unmounted(SDCARD_ROOT);
         return INSTALL_ERROR;
     }