tracing: Use ? : shortcut in trace macros

tracing: Use ? : shortcut in trace macros

Instead of having:

  #define __assign_str(dst, src)					\
	memcpy(__get_str(dst), __data_offsets.dst##_ptr_ ?		\
		__data_offsets.dst##_ptr_ : "(null)",			\
		__get_dynamic_array_len(dst))

Use the ? : shortcut and compact it down to:

  #define __assign_str(dst, src)					\
	memcpy(__get_str(dst), __data_offsets.dst##_ptr_ ? : "(null)",	\
	       __get_dynamic_array_len(dst))

Link: https://lore.kernel.org/linux-trace-kernel/[email protected]
Cc: Masami Hiramatsu <[email protected]>
Cc: Mark Rutland <[email protected]>
Cc: Andrew Morton <[email protected]>
Cc: Ville Syrjälä <[email protected]>
Cc: Rodrigo Vivi <[email protected]>
Cc: Chuck Lever <[email protected]>
Suggested-by: Mathieu Desnoyers <[email protected]>
Signed-off-by: Steven Rostedt (Google) <[email protected]>