MdePkg BaseUefiDecompressLib: Fix UEFI Decompression logic issue

https://bugzilla.tianocore.org/show_bug.cgi?id=1317

This is a regression issue caused by 2ec7953d49.
In Decode() function, once mOutBuf is fully filled, Decode() should return.
Current logic misses the checker of mOutBuf after while() loop.

Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Liming Gao <liming.gao@intel.com>
Cc: Michael Kinney <michael.d.kinney@intel.com>
Reviewed-by: Yonghong Zhu <yonghong.zhu@intel.com>

MdePkg/Library/BaseUefiDecompressLib/BaseUefiDecompressLib.c

@@ -641,6 +641,12 @@ Decode (
 
         BytesRemain--;
       }
+      //
+      // Once mOutBuf is fully filled, directly return
+      //
+      if (Sd->mOutBuf >= Sd->mOrigSize) {
+        goto Done;
+      }
     }
   }