manager: add getBlobManager as an exported method

getBlobManager will allow a library to get ahold of the BlobManager for
registration purposes.

Change-Id: I75f41601d10d59293c7752da8307507cc2c88434
Signed-off-by: Patrick Venture <venture@google.com>
diff --git a/manager.cpp b/manager.cpp
index 9a87b4f..5ab7eb3 100644
--- a/manager.cpp
+++ b/manager.cpp
@@ -15,6 +15,7 @@
  */
 
 #include <blobs-ipmid/manager.hpp>
+#include <memory>
 #include <string>
 #include <vector>
 
@@ -343,4 +344,17 @@
 
     return false;
 }
+
+static std::unique_ptr<BlobManager> manager;
+
+BlobManager* getBlobManager()
+{
+    if (manager == nullptr)
+    {
+        manager = std::make_unique<BlobManager>();
+    }
+
+    return manager.get();
+}
+
 } // namespace blobs