fix: add stdlib to fix build (#153)

pclsync/pdevice.c

@@ -31,6 +31,7 @@
 
 #include <dirent.h>
 #include <fcntl.h>
+#include <stdlib.h>
 #include <string.h>
 #include <unistd.h>
 

pclsync/prun.c

@@ -1,4 +1,5 @@
 #include <pthread.h>
+#include <stdlib.h>
 
 #include "psettings.h"
 #include "prun.h"