f2fs: merge f2fs_show_injection_info() into time_to_inject()

There is no need to additionally use f2fs_show_injection_info()
to output information. Concatenate time_to_inject() and
__time_to_inject() via a macro. In the new __time_to_inject()
function, pass in the caller function name and parent function.

In this way, we no longer need the f2fs_show_injection_info() function,
and let's remove it.

Suggested-by: Chao Yu <chao@kernel.org>
Signed-off-by: Yangtao Li <frank.li@vivo.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>