Merge commit 'e50e654b' into master

Commit e50e654b ("Add --trace support (in blktrace format)") is a broken
version of commit ef0c8360 ("Add --trace support (in blktrace
format)") that appears in master's linear history. Merging e50e654b
preserves the ability to bisect the openbmc/openbmc respository.

The merge was performed as below, which discards any changes performed
in e50e654b:

> $ git merge -s ours e50e654b

Change-Id: I134be5a54303a561ed3ef21813b1e220c0dbd0a6
Signed-off-by: Andrew Jeffery <andrew@aj.id.au>