Fix memory overflow.

git-svn-id: https://edk2.svn.sourceforge.net/svnroot/edk2/trunk/edk2@7203 6f19259b-4bc3-4df7-8a09-765794883524

MdePkg/Library/BasePrintLib/PrintLibInternal.c

@@ -77,10 +77,16 @@ BasePrintLibFillBuffer (
   )
 {
   INTN  Index;
-
+  if(Increment != 1) {
     for (Index = 0; Index < Length && Buffer < EndBuffer; Index++) {
       *Buffer       =  (CHAR8) Character;
       *(Buffer + 1) =  (CHAR8) (Character >> 8);
+    }
+    Buffer += Increment;
+  } else {
+    for (Index = 0; Index < Length && Buffer < EndBuffer; Index++) {
+      *Buffer       =  (CHAR8) Character;
+    }
     Buffer += Increment;
   }
   return Buffer;