ArmPkg/BdsFilePath: fix kernel args limitation

The limitation is corrected to 512 unicode characters, not ascii
characters.

Signed-off-by: Haojian Zhuang <haojian.zhuang@linaro.org>
diff --git a/ArmPkg/Library/BdsLib/BdsFilePath.c b/ArmPkg/Library/BdsLib/BdsFilePath.c
index 61a8bfd..07110e3 100644
--- a/ArmPkg/Library/BdsLib/BdsFilePath.c
+++ b/ArmPkg/Library/BdsLib/BdsFilePath.c
@@ -1420,7 +1420,7 @@
   if (StrnCmp (KernelArgs, BdsLoadOption->OptionalData,

                BOOTIMG_KERNEL_ARGS_SIZE) != 0) {

     ASSERT (BdsLoadOption->OptionalData != NULL);

-    ASSERT (StrSize (KernelArgs) <= BOOTIMG_KERNEL_ARGS_SIZE);

+    ASSERT (StrSize (KernelArgs) <= BOOTIMG_KERNEL_ARGS_SIZE * sizeof (CHAR16));

 

     UnicodeSPrint (InitrdArgs, 64 * sizeof(CHAR16), L" initrd=0x%x,0x%x",

 		   Header->RamdiskAddress, Header->RamdiskSize);

@@ -1440,7 +1440,7 @@
     ZeroMem (SerialNoArgs, 40 * sizeof (CHAR16));

     UnicodeSPrint (SerialNoArgs, 40 * sizeof(CHAR16), L" androidboot.serialno=%s", DataUnicode);

     StrCat (KernelArgs, SerialNoArgs);

-    ASSERT (StrSize (KernelArgs) <= BOOTIMG_KERNEL_ARGS_SIZE);

+    ASSERT (StrSize (KernelArgs) <= BOOTIMG_KERNEL_ARGS_SIZE * sizeof (CHAR16));

     if (gArgs != NULL) {

       CopyMem ((VOID *)gArgs,

                (VOID *)KernelArgs,