tracing/uprobes: Do not print '0x (null)' when offset is 0
tracing/uprobes: Do not print '0x (null)' when offset is 0

When manually added uprobe point with zero address, 'uprobe_events'
output '(null)' instead of 0x00000000:

  # echo p:probe_libc/abs_0 /path/to/lib.bin:0x0 arg1=%ax > \
            /sys/kernel/debug/tracing/uprobe_events

  # cat /sys/kernel/debug/tracing/uprobe_events
    p:probe_libc/abs_0 /path/to/lib.bin:0x          (null) arg1=%ax

 This patch fixes this behavior:

  # cat /sys/kernel/debug/tracing/uprobe_events
  p:probe_libc/abs_0 /path/to/lib.bin:0x0000000000000000

Signed-off-by: Wang Nan <7b589a40e0ecd4816b422e8ed1f74a01c34bf6bb@huawei.com>
Acked-by: Masami Hiramatsu <60fcdccfd958d359debfe6e6e7417cd7f1aaa9e3@hitachi.com>
Cc: Namhyung Kim <5c915a589b3ddf58cebf14bec41bcc143b37ac3c@kernel.org>
Cc: Steven Rostedt <43232e92d70cc7aa53504ad0397085ee47bad87f@goodmis.org>
Cc: Zefan Li <a8167b9d27aca9c6624754deb52c4c6420eded04@huawei.com>
Cc: d3a709cba82ff13e91126748cd399b3cb8e95d2e@163.com
Link: http://lkml.kernel.org/r/1440586666-235233-8-git-send-email-7b589a40e0ecd4816b422e8ed1f74a01c34bf6bb@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <293abb6b76d7791c0732cc517d38c4b5c734b87f@redhat.com>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs