uml: fix compile error in deliver_alarm()

Fix the following compile error on UML.

arch/um/os-Linux/time.c: In function 'deliver_alarm':
arch/um/os-Linux/time.c:117:3: error: too few arguments to function 'alarm_handler'
arch/um/os-Linux/internal.h:1:6: note: declared here

The error was introduced by commit d3c1cfcd ("um: pass siginfo to guest
process") in 3.6-rc1.

Signed-off-by: Miklos Szeredi <[e-mail]>
CC: Martin Pärtel <[e-mail]>
Signed-off-by: Linus Torvalds <[e-mail]>

arch/um/os-Linux/time.c

···
 	skew += this_tick - last_tick;
 
 	while (skew >= one_tick) {
-		alarm_handler(SIGVTALRM, NULL);
+		alarm_handler(SIGVTALRM, NULL, NULL);
 		skew -= one_tick;
 	}