tools:acrn-crashlog: check the folder size by calculating the increment

This patch refines the process of log space check.
Check a folder's size need to traverse all nodes of files and subdirs,
in the case of extreme memory strain, accessing these log file nodes
frequently will increase the IO pressure on the eMMC.
Previously, all log files will be accessed and counted in each space
check, this patch refines it by only calculating the increment of new logs.

Tracked-On: #1024
Signed-off-by: Liu, Xinwu <xinwu.liu@intel.com>
Reviewed-by: Liu, Xiaojing <xiaojing.liu@intel.com>
Acked-by: Chen, Gang <gang.c.chen@intel.com>

tools/acrn-crashlog/acrnprobe/include/load_conf.h

@@ -137,6 +137,7 @@ struct sender_t {
 
 	void (*send)(struct event_t *);
 	struct vmrecord_t vmrecord;
+	size_t		outdir_blocks_size;
 	int		sw_updated; /* each sender has their own record */
 };