Use helpers to obtain task pid in printks

The task_struct->pid member is going to be deprecated, so start
using the helpers (task_pid_nr/task_pid_vnr/task_pid_nr_ns) in
the kernel.

The first thing to start with is the pid, printed to dmesg - in
this case we may safely use task_pid_nr(). Besides, printks produce
more (much more) than a half of all the explicit pid usage.

[akpm@linux-foundation.org: git-drm went and changed lots of stuff]
Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Cc: Dave Airlie <airlied@linux.ie>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/drivers/cdrom/cdrom.c b/drivers/cdrom/cdrom.c
index d70745c..af05610 100644
--- a/drivers/cdrom/cdrom.c
+++ b/drivers/cdrom/cdrom.c
@@ -1107,7 +1107,7 @@
 		       is the default case! */
 		    cdinfo(CD_OPEN, "bummer. wrong media type.\n"); 
 		    cdinfo(CD_WARNING, "pid %d must open device O_NONBLOCK!\n",
-					(unsigned int)current->pid); 
+					(unsigned int)task_pid_nr(current));
 		    ret=-EMEDIUMTYPE;
 		    goto clean_up_and_return;
 		}