[KERNEL]: Some sparse fixes for init/main.c

1) Explicitly cast to __user in syscall invocations
   where we know we are in KERNEL_DS
2) Explicitly test against zero in assignment expression
   conditional.

init/main.c

@@ -186,7 +186,7 @@ void __devinit calibrate_delay(void)
 	loops_per_jiffy = (1<<12);
 
 	printk("Calibrating delay loop... ");
-	while (loops_per_jiffy <<= 1) {
+	while ((loops_per_jiffy <<= 1) != 0) {
 		/* wait for "start of" clock tick */
 		ticks = jiffies;
 		while (ticks == jiffies)
@@ -632,7 +632,7 @@ static int init(void * unused)
 	 * check if there is an early userspace init.  If yes, let it do all
 	 * the work
 	 */
-	if (sys_access("/init", 0) == 0)
+	if (sys_access((const char __user *) "/init", 0) == 0)
 		execute_command = "/init";
 	else
 		prepare_namespace();
@@ -646,7 +646,7 @@ static int init(void * unused)
 	unlock_kernel();
 	system_state = SYSTEM_RUNNING;
 
-	if (sys_open("/dev/console", O_RDWR, 0) < 0)
+	if (sys_open((const char __user *) "/dev/console", O_RDWR, 0) < 0)
 		printk("Warning: unable to open an initial console.\n");
 
 	(void) sys_dup(0);