spinlock_debug: Print offset in addition to symbol name

If one has two spinlocks embedded in a structure that kallsyms
knows about and one of the spinlocks locks up we will print the
name of the containing structure instead of the address of the
lock. This is quite bad, so let's use %pS instead of %ps so we
get an offset into the symbol so we can determine which lock is
having problems.

Change-Id: If6fbb2eb2316b846d96da76c35fcfeadbef64401
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>