(testsuite) Check rpm -q completion against actual installed packages.

While at it, drop --eval completion test because I couldn't get it to
work with assert_complete (probably because I couldn't escape the
command properly here, see --eval|-E completion in contrib/rpm), and
no longer needed match_max fiddling.

test/lib/completions/rpm.exp

@@ -8,9 +8,6 @@ proc teardown {} {
 }; # teardown()
 
 
-set _old_match_max [match_max]
-match_max 100000
-
 setup
 
 
@@ -20,18 +17,13 @@ assert_complete_any "rpm "
 sync_after_int
 
 
-assert_complete_any "rpm -q "
-
-
-sync_after_int
-
-
-assert_complete_any "rpm --eval %"
+    # Build list of installed packages
+if {[assert_exec {rpm -qa --qf=%\{NAME\}\n | sort -u} packages]} {
+    assert_complete $packages "rpm -q "
+}; # if
 
 
 sync_after_int
 
 
 teardown
-
-match_max $_old_match_max