perf tools: Fix traceevent plugin path definitions

The plugindir_SQ definition contains $(prefix) which is not needed as
the $(libdir) definition already contains prefix in it.  This leads to
the path including an extra prefix in it, e.g. /usr/usr/lib64.

The -DPLUGIN_DIR defintion includes DESTDIR.  This is incorrect, as it
sets the plugin search path to include the value of DESTDIR.  DESTDIR is
a mechanism to install in a non-standard location such as a chroot or an
RPM build root.  In the RPM case, this leads to the search path being
incorrect after the resulting RPM is installed (or in some cases an RPM
build failure).

Remove both of these unnecessary inclusions.

Signed-off-by: Josh Boyer <jwboyer@fedoraproject.org>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/20140122150147.GK16455@hansolo.jdub.homelinux.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/lib/traceevent/Makefile

@@ -63,7 +63,7 @@ endif
 endif
 
 ifeq ($(set_plugin_dir),1)
-PLUGIN_DIR = -DPLUGIN_DIR="$(DESTDIR)/$(plugin_dir)"
+PLUGIN_DIR = -DPLUGIN_DIR="$(plugin_dir)"
 PLUGIN_DIR_SQ = '$(subst ','\'',$(PLUGIN_DIR))'
 endif
 

tools/perf/config/Makefile

@@ -600,5 +600,5 @@ perfexec_instdir_SQ = $(subst ','\'',$(perfexec_instdir))
 # Otherwise we install plugins into the global $(libdir).
 ifdef DESTDIR
 plugindir=$(libdir)/traceevent/plugins
-plugindir_SQ= $(subst ','\'',$(prefix)/$(plugindir))
+plugindir_SQ= $(subst ','\'',$(plugindir))
 endif