http_chunks: fix the accounting of consumed bytes

Prior to this change chunks were handled correctly although in verbose
mode libcurl could incorrectly warn of "Leftovers after chunking" even
if there were none.

Reported-by: Michael Kaufmann

Fixes https://github.com/curl/curl/issues/12937
Closes https://github.com/curl/curl/pull/12939

lib/http_chunks.c

@@ -152,6 +152,7 @@ static CURLcode httpchunk_readwrite(struct Curl_easy *data,
         ch->hexbuffer[ch->hexindex++] = *buf;
         buf++;
         blen--;
+        (*pconsumed)++;
       }
       else {
         char *endptr;
@@ -189,6 +190,7 @@ static CURLcode httpchunk_readwrite(struct Curl_easy *data,
 
       buf++;
       blen--;
+      (*pconsumed)++;
       break;
 
     case CHUNK_DATA:
@@ -236,6 +238,7 @@ static CURLcode httpchunk_readwrite(struct Curl_easy *data,
       }
       buf++;
       blen--;
+      (*pconsumed)++;
       break;
 
     case CHUNK_TRAILER:
@@ -293,6 +296,7 @@ static CURLcode httpchunk_readwrite(struct Curl_easy *data,
       }
       buf++;
       blen--;
+      (*pconsumed)++;
       break;
 
     case CHUNK_TRAILER_CR:
@@ -300,6 +304,7 @@ static CURLcode httpchunk_readwrite(struct Curl_easy *data,
         ch->state = CHUNK_TRAILER_POSTCR;
         buf++;
         blen--;
+        (*pconsumed)++;
       }
       else {
         ch->state = CHUNK_FAILED;
@@ -320,6 +325,7 @@ static CURLcode httpchunk_readwrite(struct Curl_easy *data,
         /* skip if CR */
         buf++;
         blen--;
+        (*pconsumed)++;
       }
       /* now wait for the final LF */
       ch->state = CHUNK_STOP;
@@ -328,6 +334,7 @@ static CURLcode httpchunk_readwrite(struct Curl_easy *data,
     case CHUNK_STOP:
       if(*buf == 0x0a) {
         blen--;
+        (*pconsumed)++;
         /* Record the length of any data left in the end of the buffer
            even if there's no more chunks to read */
         ch->datasize = blen;