libperf: Fix install_pkgconfig target

Commit 47e02b9 ("tools lib perf: Add dependency test to install_headers")
misses the notion of $(DESTDIR_SQ) for install_pkgconfig target, which leads to
error:

  install: cannot create regular file '/usr/lib64/pkgconfig/libperf.pc': Permission denied
  make: *** [Makefile:210: install_pkgconfig] Error 1

Signed-off-by: Alexander Gordeev <[email protected]>
Cc: Alexander Shishkin <[email protected]>
Cc: Ian Rogers <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Josh Poimboeuf <[email protected]>
Cc: Mark Rutland <[email protected]>
Cc: Masahiro Yamada <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Nathan Chancellor <[email protected]>
Cc: Nick Desaulniers <[email protected]>
Cc: Nicolas Schier <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Stephane Eranian <[email protected]>
Cc: Tom Rix <[email protected]>
Cc: [email protected]
Cc: [email protected]
Link: http://lore.kernel.org/lkml/Y5w/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>

Author: Alexander Gordeev

tools/lib/perf/Makefile

@@ -208,7 +208,7 @@ install_headers: $(INSTALL_HDRS) $(INSTALL_INTERNAL_HDRS)
 
 install_pkgconfig: $(LIBPERF_PC)
 	$(call QUIET_INSTALL, $(LIBPERF_PC)) \
-		$(call do_install,$(LIBPERF_PC),$(libdir_SQ)/pkgconfig,644)
+		$(call do_install,$(LIBPERF_PC),$(DESTDIR_SQ)$(libdir_SQ)/pkgconfig,644)
 
 install_doc:
 	$(Q)$(MAKE) -C Documentation install-man install-html install-examples