alpha: invoke oom-killer from page fault

As explained in commit 1c0fe6e3bd, we want to call the architecture
independent oom killer when getting an unexplained OOM from
handle_mm_fault, rather than simply killing current.

[mattst88: kill now unused 'survive' label]
Cc: [e-mail]
Cc: Richard Henderson <[e-mail]>
Cc: [e-mail]
Acked-by: David Rientjes <[e-mail]>
Signed-off-by: Matt Turner <[e-mail]>
Signed-off-by: Nick Piggin <[e-mail]>

arch/alpha/mm/fault.c

···
 			goto bad_area;
 	}
 
- survive:
 	/* If for any reason at all we couldn't handle the fault,
 	   make sure we exit gracefully rather than endlessly redo
 	   the fault.  */
···
 	/* We ran out of memory, or some other thing happened to us that
 	   made us unable to handle the page fault gracefully.  */
  out_of_memory:
-	if (is_global_init(current)) {
-		yield();
-		down_read(&mm->mmap_sem);
-		goto survive;
-	}
-	printk(KERN_ALERT "VM: killing process %s(%d)\n",
-	       current->comm, task_pid_nr(current));
 	if (!user_mode(regs))
 		goto no_context;
-	do_group_exit(SIGKILL);
+	pagefault_out_of_memory();
+	return;
 
  do_sigbus:
 	/* Send a sigbus, regardless of whether we were in kernel