mm/khugepaged: add tracepoint to collapse_file()

"mm_khugepaged_collapse_file" for capturing is_shmem.
Currently, is_shmem is not being captured. Capturing is_shmem is useful
as it can indicate if tmpfs is being used as a backing store instead of
persistent storage. Add the tracepoint in collapse_file() named
"mm_khugepaged_collapse_file" for capturing is_shmem.

[gautammenghani201@gmail.com: swap is_shmem and addr to save space, per Steven Rostedt]
  Link: https://lkml.kernel.org/r/20221202201807.182829-1-gautammenghani201@gmail.com
Link: https://lkml.kernel.org/r/20221026052218.148234-1-gautammenghani201@gmail.com


Signed-off-by: Gautam Menghani <gautammenghani201@gmail.com>
Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>	[tracing]
Cc: David Hildenbrand <david@redhat.com>
Cc: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Cc: Yang Shi <shy828301@gmail.com>
Cc: Zach O'Keefe <zokeefe@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>