printk: change type of 'boot_delay' to int *

get_option() takes its 2nd arg as int * so passing boot_delay to it
caused following warnings from sparse:

 kernel/printk.c:223:27: warning: incorrect type in argument 2 (different signedness)
 kernel/printk.c:223:27:    expected int *pint
 kernel/printk.c:223:27:    got unsigned int static [toplevel] *<noident>

Since boot_delay can't grow more than 10,000 changing it to 'int *'
will not produce any problem.
Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

kernel/printk.c

@@ -210,7 +210,7 @@ __setup("log_buf_len=", log_buf_len_setup);
 
 #ifdef CONFIG_BOOT_PRINTK_DELAY
 
-static unsigned int boot_delay; /* msecs delay after each printk during bootup */
+static int boot_delay; /* msecs delay after each printk during bootup */
 static unsigned long long loops_per_msec;	/* based on boot_delay */
 
 static int __init boot_delay_setup(char *str)