trace-cmd,Makefile: Use find instead of locate to find docbook.xsl
trace-cmd,Makefile: Use find instead of locate to find docbook.xsl

Change the current hack to use locate to find a docbook.xsl to use for
creating man pages with another hack that uses find /usr instead. This
has a better chance of finding a correct docbook.xsl especially if the
updatedb database hasn't been set up yet.

Signed-off-by: Steven Rostedt <43232e92d70cc7aa53504ad0397085ee47bad87f@goodmis.org>

bigzz/trace-cmd,bigzz/trace-cmd