pkg-config: use PKG_INSTALLDIR [review]

configure.ac

@@ -41,11 +41,8 @@ LT_INIT
 
 # Use pkg-config
 PKG_PROG_PKG_CONFIG
-AC_CHECK_PROG(PKG_CONFIG, pkg-config, yes)
-AM_CONDITIONAL([HAVE_PKG_CONFIG], [test "x$PKG_CONFIG" != "x"])
-AS_IF([test "x$PKG_CONFIG" != "x"], [
-    AC_CONFIG_FILES([libknot.pc])
-])
+PKG_INSTALLDIR
+AC_CONFIG_FILES([libknot.pc])
 
 AC_CACHE_CHECK([for reentrant lex], [ac_cv_path_LEX],
   [AC_PATH_PROGS_FEATURE_CHECK([LEX], [$LEX flex gflex],

src/Makefile.am

@@ -349,11 +349,6 @@ khost_LDADD      = $(BIN_LIBS) $(libidn_LIBS)
 knsupdate_LDADD  = $(BIN_LIBS) zscanner/libzscanner.la
 knsec3hash_LDADD = $(BIN_LIBS)
 
-if HAVE_PKG_CONFIG
-pkgconfigdir = $(libdir)/pkgconfig
-pkgconfig_DATA = $(top_srcdir)/libknot.pc
-endif
-
 if HAVE_DNSTAP
 libknotd_la_SOURCES +=				\
 	knot/modules/dnstap.c			\
@@ -364,6 +359,9 @@ khost_LDADD        += dnstap/libdnstap.la
 libknotd_la_LIBADD += dnstap/libdnstap.la
 endif
 
+# pkg-config
+pkgconfig_DATA = $(top_srcdir)/libknot.pc
+
 # Create storage and run-time directories
 install-data-hook:
 	$(INSTALL) -d $(DESTDIR)/@config_dir@