CCBC-1596: Fix signatures to match declaration with (void) for arg list

contrib/cJSON/cJSON.c:924:24: warning: a function declaration without a prototype is deprecated in all versions of C [-Wstrict-prototypes]
cJSON *cJSON_CreateNull()
                       ^
contrib/cJSON/cJSON.c:930:24: warning: a function declaration without a prototype is deprecated in all versions of C [-Wstrict-prototypes]
cJSON *cJSON_CreateTrue()
                       ^
contrib/cJSON/cJSON.c:936:25: warning: a function declaration without a prototype is deprecated in all versions of C [-Wstrict-prototypes]
cJSON *cJSON_CreateFalse()
                        ^
contrib/cJSON/cJSON.c:965:25: warning: a function declaration without a prototype is deprecated in all versions of C [-Wstrict-prototypes]
cJSON *cJSON_CreateArray()
                        ^
contrib/cJSON/cJSON.c:971:26: warning: a function declaration without a prototype is deprecated in all versions of C [-Wstrict-prototypes]
cJSON *cJSON_CreateObject()
                         ^

contrib/HdrHistogram_c/src/hdr_thread.c:91:15: warning: a function declaration without a prototype is deprecated in all versions of C [-Wstrict-prototypes]
void hdr_yield()
              ^

Change-Id: I6edd9079406a6fd3132b9c54710076dfd4855fb9
Reviewed-on: https://review.couchbase.org/c/libcouchbase/+/190105
Reviewed-by: Brett Lawson <brett19@gmail.com>
Reviewed-by: Trond Norbye <trond.norbye@couchbase.com>
Tested-by: Build Bot <build@couchbase.com>

Author: avsej

contrib/HdrHistogram_c/src/hdr_thread.c

@@ -88,7 +88,7 @@ void hdr_mutex_unlock(struct hdr_mutex* mutex)
     pthread_mutex_unlock(&mutex->_mutex);
 }
 
-void hdr_yield()
+void hdr_yield(void)
 {
     sched_yield();
 }

contrib/cJSON/cJSON.c

@@ -921,19 +921,19 @@ void cJSON_ReplaceItemInObject(cJSON *object, const char *string, cJSON *newitem
 }
 
 /* Create basic types: */
-cJSON *cJSON_CreateNull()
+cJSON *cJSON_CreateNull(void)
 {
     cJSON *item = cJSON_New_Item(0);
     item->type = cJSON_NULL;
     return item;
 }
-cJSON *cJSON_CreateTrue()
+cJSON *cJSON_CreateTrue(void)
 {
     cJSON *item = cJSON_New_Item(0);
     item->type = cJSON_True;
     return item;
 }
-cJSON *cJSON_CreateFalse()
+cJSON *cJSON_CreateFalse(void)
 {
     cJSON *item = cJSON_New_Item(0);
     item->type = cJSON_False;
@@ -962,13 +962,13 @@ cJSON *cJSON_CreateString(const char *string)
     item->valuestring = cJSON_strdup(string);
     return item;
 }
-cJSON *cJSON_CreateArray()
+cJSON *cJSON_CreateArray(void)
 {
     cJSON *item = cJSON_New_Item(0);
     item->type = cJSON_Array;
     return item;
 }
-cJSON *cJSON_CreateObject()
+cJSON *cJSON_CreateObject(void)
 {
     cJSON *item = cJSON_New_Item(0);
     item->type = cJSON_Object;