Fixed yasm/nasm warning.

  Fixes Bugzilla #446.

--HG--
branch : SDL-1.2
extra : convert_revision : svn%3Ac70aab31-4412-0410-b14c-859654838e24/branches/SDL-1.2%402402

src/hermes/mmxp2_32.asm

@@ -283,7 +283,7 @@ _convert_bgr555_cheat:
         
 	mov edx,ecx		           ; Save ecx 
 
-        and ecx,BYTE 0fffffff8h            ; clear lower three bits
+        and ecx,DWORD 0fffffff8h            ; clear lower three bits
 	jnz .L_OK
         jmp near .L2