Replace conditional GC_log_printf calls with GC_COND/VERBOSE_LOG_PRINTF

Replace conditional GC_log_printf calls with GC_COND/VERBOSE_LOG_PRINTF
(code refactoring)

* allchblk.c (GC_freehblk): Replace
"if (GC_print_stats) GC_log_printf" with GC_COND_LOG_PRINTF.
* alloc.c (GC_timeout_stop_func, GC_maybe_gc, GC_try_to_collect_inner,
GC_stopped_mark, GC_finish_collection, GC_expand_hp_inner,
GC_collect_or_expand): Likewise.
* backgraph.c (backwards_height, GC_print_back_graph_stats): Likewise.
* checksums.c (GC_check_blocks, GC_check_dirty): Likewise.
* dyn_load.c (GC_register_dynamic_libraries): Likewise.
* finalize.c (GC_general_register_disappearing_link,
GC_register_finalizer_inner): Likewise.
* gcj_mlc.c (GC_init_gcj_malloc): Likewise.
* headers.c (GC_scratch_alloc): Likewise.
* mark.c (GC_mark_some_inner, GC_mark_some,
GC_signal_mark_stack_overflow, GC_return_mark_stack,
alloc_mark_stack): Likewise.
* obj_map.c (GC_add_map_entry): Likewise.
* os_dep.c (GC_get_maps, backing_store_base_from_proc,
GC_register_data_segments, detect_GetWriteWatch,
GC_add_current_malloc_heap, GC_remap, PROTECT, GC_write_fault_handler,
GC_dirty_init, GC_mprotect_thread): Likewise.
* pthread_stop_world.c (GC_stop_world, GC_start_world, GC_stop_init):
Likewise.
* pthread_support.c (start_mark_threads, GC_thr_init): Likewise.
* win32_threads.c (GC_register_my_thread_inner, GC_thr_init):
Likewise.
* alloc.c (GC_finish_collection): Replace
"if (GC_print_stats == VERBOSE) GC_log_printf" with
GC_VERBOSE_LOG_PRINTF.
* blacklst.c (GC_promote_black_lists): Likewise.
* darwin_stop_world.c (GC_push_all_stacks): Likewise.
* mark.c (GC_mark_local, GC_do_parallel_mark): Likewise.
* os_dep.c (GC_dirty_init): Likewise.
* pthread_stop_world.c (GC_push_all_stacks): Likewise.
* win32_threads.c (GC_push_all_stacks): Likewise.
* include/private/gc_priv.h (GC_COND_LOG_PRINTF,
GC_VERBOSE_LOG_PRINTF): New macro (check GC_print_stats and call
GC_log_printf if enabled).
* os_dep.c (GC_dirty_init, GC_read_dirty): Replace
"if (GC_print_stats) GC_err_printf" with WARN.