Move test-suite dbpath setup to macros.testenv too

Somehow missed this opportunity in add3e06.
With this and 78c21f4, we really now
have a central place to configure system-wide macros in a prefix
independent manner.

tests/data/macros.testenv

@@ -2,3 +2,4 @@
 %_buildhost testhost
 %_topdir %{getenv:RPMTEST}/build
 %_tmppath %{getenv:RPMTEST}/var/tmp
+%_dbpath /var/lib/rpm-testsuite

tests/setup.sh

@@ -7,15 +7,12 @@ export DESTDIR=${1:-/}
 mkdir -p $DESTDIR/build
 ln -sf ../data/SOURCES $DESTDIR/build/
 
-# setup an empty db that all tests are pointed to by default
-dbpath="/var/lib/rpm-testsuite"
-mkdir -p $DESTDIR/$dbpath
-echo "%_dbpath $dbpath" > $DESTDIR/@CMAKE_INSTALL_FULL_SYSCONFDIR@/rpm/macros.db
-rpmdb --dbpath $DESTDIR/$dbpath --initdb
-
 # system-wide config to match our test environment
 cp /data/macros.testenv $DESTDIR/@CMAKE_INSTALL_FULL_SYSCONFDIR@/rpm/
 
+# setup an empty db that all tests are pointed to by default
+rpmdb --dbpath $DESTDIR/$(rpm --eval "%{_dbpath}") --initdb
+
 # gpg-connect-agent is very, very unhappy if this doesn't exist
 mkdir -p $DESTDIR/root/.gnupg
 chmod 700 $DESTDIR/root/.gnupg