BaseTools: fix the bug to add PaletteSize info into AutoGen

Fix the bug to add PaletteSize info into AutoGen.c when the flag
UEFI_HII_RESOURCE_SECTION is set to FALSE.

Cc: Liming Gao <liming.gao@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Yonghong Zhu <yonghong.zhu@intel.com>
Reviewed-by: Liming Gao <liming.gao@intel.com>
diff --git a/BaseTools/Source/Python/AutoGen/GenC.py b/BaseTools/Source/Python/AutoGen/GenC.py
index de6eb0e..63cfe04 100644
--- a/BaseTools/Source/Python/AutoGen/GenC.py
+++ b/BaseTools/Source/Python/AutoGen/GenC.py
@@ -1695,10 +1695,11 @@
                                 TempBuffer, TempPalette = BmpImageDecoder(File, Buffer, PaletteIndex, FileObj.TransParent)

                                 if len(TempPalette) > 1:

                                     PaletteIndex += 1

-                                    PaletteBuffer += pack('H', len(TempPalette))

-                                    PaletteBuffer += TempPalette

+                                    NewPalette = pack('H', len(TempPalette))

+                                    NewPalette += TempPalette

+                                    PaletteBuffer += NewPalette

                                     PaletteStr = WriteLine(PaletteStr, '// %s: %s: %s' % (DecToHexStr(PaletteIndex - 1, 4), ID, DecToHexStr(PaletteIndex - 1, 4)))

-                                    TempPaletteList = AscToHexList(TempPalette)

+                                    TempPaletteList = AscToHexList(NewPalette)

                                     PaletteStr = WriteLine(PaletteStr, CreateArrayItem(TempPaletteList, 16) + '\n')

                             ImageBuffer += TempBuffer

                             BufferStr = WriteLine(BufferStr, '// %s: %s: %s' % (DecToHexStr(Index, 4), ID, DecToHexStr(Index, 4)))