[build] Port to newer automake recommended syntax
diff --git a/test/api/Makefile.am b/test/api/Makefile.am
index cc0c3e9..0ed943b 100644
--- a/test/api/Makefile.am
+++ b/test/api/Makefile.am
@@ -95,8 +95,8 @@
$(EXTRA_VALGRIND_FLAGS)
# Can't do for now: --show-reachable=yes
CLEANFILES += log-valgrind.txt
-valgrind_verbose = $(valgrind_verbose_$(V))
-valgrind_verbose_ = $(valgrind_verbose_$(AM_DEFAULT_VERBOSITY))
+valgrind_verbose = $(valgrind_verbose_@AM_V@)
+valgrind_verbose_ = $(valgrind_verbose_@AM_DEFAULT_V@)
valgrind_verbose_0 = | \
grep '\(^[^=]\|ERROR SUMMARY\|definitely lost\|indirectly lost\)' | grep -v ': 0'
# TODO: The following check does not fail if valgrind finds error. It should.
