Replace malloc + memset with calloc where appropriate

calloc is faster for big allocations. It's also simpler.

Signed-off-by: Rosen Penev <rosenp@gmail.com>
diff --git a/libcnary/node.c b/libcnary/node.c
index c24ca7a..6d68f6e 100644
--- a/libcnary/node.c
+++ b/libcnary/node.c
@@ -46,11 +46,10 @@
 node_t* node_create(node_t* parent, void* data) {
 	int error = 0;
 
-	node_t* node = (node_t*) malloc(sizeof(node_t));
-	if(node == NULL) {
+	node_t* node = (node_t*)calloc(1, sizeof(node_t));
+	if (node == NULL) {
 		return NULL;
 	}
-	memset(node, '\0', sizeof(node_t));
 
 	node->data = data;
 	node->next = NULL;
diff --git a/libcnary/node_list.c b/libcnary/node_list.c
index d071881..aee3bd6 100644
--- a/libcnary/node_list.c
+++ b/libcnary/node_list.c
@@ -33,11 +33,10 @@
 }
 
 node_list_t* node_list_create() {
-	node_list_t* list = (node_list_t*) malloc(sizeof(node_list_t));
-	if(list == NULL) {
+	node_list_t* list = (node_list_t*)calloc(1, sizeof(node_list_t));
+	if (list == NULL) {
 		return NULL;
 	}
-	memset(list, '\0', sizeof(node_list_t));
 
 	// Initialize structure
 	list->begin = NULL;
diff --git a/src/xplist.c b/src/xplist.c
index 3a92142..2f98983 100644
--- a/src/xplist.c
+++ b/src/xplist.c
@@ -211,8 +211,7 @@
             struct TM _btime;
             struct TM *btime = gmtime64_r(&timev, &_btime);
             if (btime) {
-                val = (char*)malloc(24);
-                memset(val, 0, 24);
+                val = (char*)calloc(1, 24);
                 struct tm _tmcopy;
                 copy_TM64_to_tm(btime, &_tmcopy);
                 val_len = strftime(val, 24, "%Y-%m-%dT%H:%M:%SZ", &_tmcopy);
diff --git a/tools/plistutil.c b/tools/plistutil.c
index 989db35..fd0847b 100644
--- a/tools/plistutil.c
+++ b/tools/plistutil.c
@@ -69,8 +69,7 @@
 {
     int i = 0;
 
-    options_t *options = (options_t *) malloc(sizeof(options_t));
-    memset(options, 0, sizeof(options_t));
+    options_t *options = (options_t*)calloc(1, sizeof(options_t));
     options->out_fmt = 0;
 
     for (i = 1; i < argc; i++)