build: remove now-useless --{en, dis}able-tests

commit d771020 "don't build tests unless make check is run" has made the
 --{en,dis}able-tests switch completely useless.  The differentiation is
now made by running "make check" or not doing so.  The only effect of
the switch is an "empty" excursion of make into the tests/ directory.

(well, and it turns "make check" useless from the main directory if
 --disable-tests is given, which I don't think makes sense either)

Acked-by: Greg Troxel <gdt@ir.bbn.com>
Signed-off-by: David Lamparter <equinox@opensourcerouting.org>

Makefile.am

@@ -2,7 +2,7 @@
 
 SUBDIRS = lib @ZEBRA@ @BGPD@ @RIPD@ @RIPNGD@ @OSPFD@ @OSPF6D@ @BABELD@ \
          @ISISD@ @WATCHQUAGGA@ @VTYSH@ @OSPFCLIENT@ @DOC@ m4 @pkgsrcdir@ \
-         redhat @SOLARIS@ @BUILD_TESTS@
+         redhat @SOLARIS@ tests
 
 DIST_SUBDIRS = lib zebra bgpd ripd ripngd ospfd ospf6d babeld \
 	  isisd watchquagga vtysh ospfclient doc m4 pkgsrc redhat tests \

configure.ac

@@ -202,8 +202,6 @@ AC_ARG_ENABLE(ipv6,
 [  --disable-ipv6          turn off IPv6 related features and daemons])
 AC_ARG_ENABLE(doc,
 [  --disable-doc           do not build docs])
-AC_ARG_ENABLE(tests,
-[  --disable-tests         do not build tests])
 AC_ARG_ENABLE(zebra,
 [  --disable-zebra         do not build zebra daemon])
 AC_ARG_ENABLE(bgpd,
@@ -1272,13 +1270,6 @@ else
   DOC="doc"
 fi
 
-dnl can't use TESTS as name, that's special with automake
-if test "${enable_tests}" = "no";then
-  BUILD_TESTS=""
-else
-  BUILD_TESTS="tests"
-fi
-
 dnl --------------------
 dnl Daemon disable check
 dnl --------------------
@@ -1372,7 +1363,6 @@ else
 fi
 
 AC_SUBST(DOC)
-AC_SUBST(BUILD_TESTS)
 AC_SUBST(ZEBRA)
 AC_SUBST(BGPD)
 AC_SUBST(RIPD)

doc/install.texi

@@ -90,12 +90,6 @@ Enable support for Equal Cost Multipath. @var{ARG} is the maximum number
 of ECMP paths to allow, set to 0 to allow unlimited number of paths.
 @item --disable-rtadv
 Disable support IPV6 router advertisement in zebra.
-@item --disable-tests
-Do not build tests.  Test programs are built by default, but not ran or
-installed.  They can be excluded from build with this option, which will
-minimally decrease compile time and overhead.  They can always be built and
-executed at a later time by running @command{make check} in the @file{tests/}
-subdirectory, even if they're excluded from build.
 @item --enable-gcc-rdynamic
 Pass the @command{-rdynamic} option to the linker driver.  This is in most
 cases neccessary for getting usable backtraces.  This option defaults to on