spinlock_debug: print kallsyms name for lock

When a spinlock warning is printed we usually get

 BUG: spinlock bad magic on CPU#0, modprobe/111
  lock: 0xdff09f38, .magic: 00000000, .owner: /0, .owner_cpu: 0

but it's nicer to print the symbol for the lock if we have it so that we
can avoid 'grep dff09f38 /proc/kallsyms' to find out which lock it was.
Use kallsyms to print the symbol name so we get something a bit easier to
read

 BUG: spinlock bad magic on CPU#0, modprobe/112
  lock: test_lock, .magic: 00000000, .owner: <none>/-1, .owner_cpu: 0

If the lock is not in kallsyms %ps will fall back to printing the address
directly.

Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>