Make pp_help a constant array of characters to move it to .rodata.

Patch by Diego 'Flameeyes' Pettenò flameeyes ¤ gmail ! com

Originally committed as revision 11487 to svn://svn.ffmpeg.org/ffmpeg/trunk

libpostproc/postprocess.c

@@ -694,7 +694,11 @@ static inline void postProcess(uint8_t src[], int srcStride, uint8_t dst[], int
 
 /* -pp Command line Help
 */
+#if LIBPOSTPROC_VERSION_INT < (52<<16)
 const char *const pp_help=
+#else
+const char pp_help[] =
+#endif
 "Available postprocessing filters:\n"
 "Filters                        Options\n"
 "short  long name       short   long option     Description\n"

libpostproc/postprocess.h

@@ -42,7 +42,11 @@
 typedef void pp_context_t;
 typedef void pp_mode_t;
 
+#if LIBPOSTPROC_VERSION_INT < (52<<16)
 extern const char *const pp_help; ///< a simple help text
+#else
+extern const char pp_help[]; ///< a simple help text
+#endif
 
 void  pp_postprocess(uint8_t * src[3], int srcStride[3],
                  uint8_t * dst[3], int dstStride[3],