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/usb/gadget/file_storage.c b/drivers/usb/gadget/file_storage.c
index 73726c5..1d174dc 100644
--- a/drivers/usb/gadget/file_storage.c
+++ b/drivers/usb/gadget/file_storage.c
@@ -4006,7 +4006,7 @@
 	DBG(fsg, "removable=%d, stall=%d, buflen=%u\n",
 			mod_data.removable, mod_data.can_stall,
 			mod_data.buflen);
-	DBG(fsg, "I/O thread pid: %d\n", fsg->thread_task->pid);
+	DBG(fsg, "I/O thread pid: %d\n", task_pid_nr(fsg->thread_task));
 
 	set_bit(REGISTERED, &fsg->atomic_bitflags);