Cleanup some errors in typedef comments and remove duplicated HOWTO from zbuff_decompress.c

lib/compress/huf_compress.c

@@ -89,7 +89,7 @@ unsigned HUF_optimalTableLog(unsigned maxTableLog, size_t srcSize, unsigned maxS
 struct HUF_CElt_s {
   U16  val;
   BYTE nbBits;
-};   /* typedef'd to HUF_CElt within huf_static.h */
+};   /* typedef'd to HUF_CElt within "huf.h" */
 
 typedef struct nodeElt_s {
     U32 count;

lib/compress/zbuff_compress.c

@@ -98,7 +98,7 @@ struct ZBUFF_CCtx_s {
     U32    checksum;
     U32    frameEnded;
     ZSTD_customMem customMem;
-};   /* typedef'd tp ZBUFF_CCtx within "zstd_buffered.h" */
+};   /* typedef'd tp ZBUFF_CCtx within "zbuff.h" */
 
 ZBUFF_CCtx* ZBUFF_createCCtx(void)
 {

lib/compress/zstd_compress.c

@@ -2694,7 +2694,7 @@ struct ZSTD_CDict_s {
     void* dictContent;
     size_t dictContentSize;
     ZSTD_CCtx* refContext;
-};  /* typedef'd tp ZSTD_CDict within zstd.h */
+};  /* typedef'd tp ZSTD_CDict within "zstd.h" */
 
 ZSTD_CDict* ZSTD_createCDict_advanced(const void* dict, size_t dictSize, ZSTD_parameters params, ZSTD_customMem customMem)
 {