Avoid the use of the Objective-C reserved name "id".

inflate.c

@@ -1275,7 +1275,7 @@ const Bytef *dictionary;
 uInt dictLength;
 {
     struct inflate_state FAR *state;
-    unsigned long id;
+    unsigned long dictid;
     unsigned char *next;
     unsigned avail;
     int ret;
@@ -1286,11 +1286,11 @@ uInt dictLength;
     if (state->wrap != 0 && state->mode != DICT)
         return Z_STREAM_ERROR;
 
-    /* check for correct dictionary id */
+    /* check for correct dictionary identifier */
     if (state->mode == DICT) {
-        id = adler32(0L, Z_NULL, 0);
-        id = adler32(id, dictionary, dictLength);
-        if (id != state->check)
+        dictid = adler32(0L, Z_NULL, 0);
+        dictid = adler32(dictid, dictionary, dictLength);
+        if (dictid != state->check)
             return Z_DATA_ERROR;
     }