perf trace: Fix documentation for -i

perf trace: Fix documentation for -i

The -i flag was incorrectly listed as a short flag for --no-inherit.  It
should have only been listed as a short flag for --input.

This documentation error has existed since the --input flag was
introduced in 6810fc915f7a89d8134edb3996dbbf8eac386c26 (perf trace: Add
option to analyze events in a file versus live).

Signed-off-by: Peter Feiner <pfeiner@google.com>
Cc: David Ahern <dsahern@gmail.com>
Link: http://lkml.kernel.org/r/1446657706-14518-1-git-send-email-pfeiner@google.com
Fixes: 6810fc915f7a ("perf trace: Add option to analyze events in a file versus live")
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>