openssh: build regression test binaries

ptests were failing and many more were being silently skipped because
required binaries were not being built.

Build the binaries in regress/ and set SUDO environment variable in
run-ptests: after this all tests in regress/ are now run. Continue to
skip building binaries in regress/unittests/: unittest runtime is
excessive.

On a NUC running intel-corei7-64 core-image-sato, new results are:
PASS: 55, SKIP: 3, FAIL: 0

[YOCTO #8153]

(From OE-Core rev: 1f7aaf76f4aa7875f05f4b838a5ec4594a4c35dc)

Signed-off-by: Jussi Kukkonen <jussi.kukkonen@intel.com>
Signed-off-by: Ross Burton <ross.burton@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

meta/recipes-connectivity/openssh/openssh/run-ptest

@@ -3,5 +3,5 @@
 export TEST_SHELL=sh
 
 cd regress
-make -k .OBJDIR=`pwd` .CURDIR=`pwd` tests \
+make -k .OBJDIR=`pwd` .CURDIR=`pwd` SUDO="sudo" tests \
         | sed -e 's/^skipped/SKIP: /g' -e 's/^ok /PASS: /g' -e 's/^failed/FAIL: /g'

meta/recipes-connectivity/openssh/openssh_7.0p1.bb

@@ -79,6 +79,12 @@ do_configure_prepend () {
 	fi
 }
 
+do_compile_ptest() {
+        # skip regress/unittests/ binaries: this will silently skip
+        # unittests in run-ptests which is good because they are so slow.
+        oe_runmake regress/modpipe regress/setuid-allowed regress/netcat
+}
+
 do_install_append () {
 	if [ "${@bb.utils.contains('DISTRO_FEATURES', 'pam', 'pam', '', d)}" = "pam" ]; then
 		install -D -m 0755 ${WORKDIR}/sshd ${D}${sysconfdir}/pam.d/sshd