Link libcommon.la with $(COMMON_LIBS).
This hopefully fixes link errors on Solaris:
CCLD test_utils_vl_lookup
Undefined first referenced
symbol in file
kstat_data_lookup daemon/.libs/libcommon.a(common.o)
kstat_lookup daemon/.libs/libcommon.a(common.o)
kstat_read daemon/.libs/libcommon.a(common.o)
getaddrinfo daemon/.libs/libcommon.a(common.o)
freeaddrinfo daemon/.libs/libcommon.a(common.o)
gai_strerror daemon/.libs/libcommon.a(common.o)
ld: fatal: symbol referencing errors. No output written to test_utils_vl_lookup
collect2: error: ld returned 1 exit status