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

Change-Id: I833d011da8362960e97c53ebd59236ac7eb147fd
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>