Update SDL2 to 2.0.4

code/SDL2/include/SDL_endian.h

@@ -1,6 +1,6 @@
 /*
   Simple DirectMedia Layer
-  Copyright (C) 1997-2014 Sam Lantinga <slouken@libsdl.org>
+  Copyright (C) 1997-2016 Sam Lantinga <slouken@libsdl.org>
 
   This software is provided 'as-is', without any express or implied
   warranty.  In no event will the authors be held liable for any damages
@@ -42,7 +42,7 @@
 #ifdef __linux__
 #include <endian.h>
 #define SDL_BYTEORDER  __BYTE_ORDER
-#else /* __linux __ */
+#else /* __linux__ */
 #if defined(__hppa__) || \
     defined(__m68k__) || defined(mc68000) || defined(_M_M68K) || \
     (defined(__MIPS__) && defined(__MISPEB__)) || \
@@ -52,7 +52,7 @@
 #else
 #define SDL_BYTEORDER   SDL_LIL_ENDIAN
 #endif
-#endif /* __linux __ */
+#endif /* __linux__ */
 #endif /* !SDL_BYTEORDER */