locking/lockdep: Remove the unused print_lock_trace() function

locking/lockdep: Remove the unused print_lock_trace() function

gcc warns that function print_lock_trace() is unused if
CONFIG_PROVE_LOCKING isn't set:

../kernel/locking/lockdep.c:2820:13: warning: ‘print_lock_trace’ defined but not used [-Wunused-function]

Rework so we remove the function if CONFIG_PROVE_LOCKING isn't set.

Signed-off-by: Anders Roxell <anders.roxell@linaro.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: will.deacon@arm.com
Fixes: c120bce78065 ("lockdep: Simplify stack trace handling")
Link: http://lkml.kernel.org/r/20190516191326.27003-1-anders.roxell@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>