Modified the kernel and all tasks with well-formatted printout messages.

tasks/libposix/errno.c

@@ -1,7 +1,13 @@
 #include <errno.h>
+#include <stdio.h>
 
 int errno_variable;
 
+void perror(const char *str)
+{
+	printf("%s: %d\n", str, errno);
+}
+
 int *__errno_location(void)
 {
 	return &errno_variable;