Fix paths for out-of-tree builds, found by make distcheck

Signed-off-by: Joachim Nilsson <troglobit@gmail.com>

test/Makefile.am

@@ -5,9 +5,9 @@ TEST_EXTENSIONS  = .sh
 
 check_PROGRAMS   = api
 api_SOURCES      = api.c
-api_CFLAGS       = -I../src
+api_CFLAGS       = -I$(srcdir)/../src
 api_LDFLAGS      = -static
-api_LDADD        = -L../src ../src/libsyslog.la
+api_LDADD        = ../src/libsyslog.la
 
 TESTS            = start.sh
 TESTS           += local.sh