MdeModulePkg/Dxe/Image: Restore mCurrentImage on all paths

This commit makes sure that in function CoreStartImage(), module
variable 'mCurrentImage' is restored to the current start image context
on all code paths.

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Hao Wu <hao.a.wu@intel.com>
Reviewed-by: Liming Gao <liming.gao@intel.com>
(cherry picked from commit 7a14d54f6c)

MdeModulePkg/Core/Dxe/Image/Image.c

@@ -1647,6 +1647,12 @@ CoreStartImage (
     //
     PERF_START (NULL, "StartImage:", NULL, Tick);
     PERF_END (NULL, "StartImage:", NULL, 0);
+
+    //
+    // Pop the current start image context
+    //
+    mCurrentImage = LastImage;
+
     return EFI_OUT_OF_RESOURCES;
   }
   Image->JumpContext = ALIGN_POINTER (Image->JumpBuffer, BASE_LIBRARY_JUMP_BUFFER_ALIGNMENT);