build: Link -losmocore last to please Ubuntu linker

It seems that the Ubuntu linker is quite picky in where it is looking
for symbols. Link libosmocore (and as such talloc) last of the Osmocom
libraries. This could fix:

gcc -Wall -I/usr/include/ -I/usr/include/ -I/usr/include/ -I/usr/include/   -DNO_UNIPORTE -g -O2 -fdebug-prefix-map=/usr/src/packages/BUILD=. -fstack-protector-strong -Wformat -Werror=format-security  -Wl,-Bsymbolic-functions -Wl,-z,relro -o cellmgr_ng main.o mtp_layer3.o thread.o ipaccess.o pcap.o bss_patch.o bssap_sccp.o bsc_sccp.o bsc_ussd.o links.o msc_conn.o link_udp.o snmp_mtp.o debug.o isup.o mtp_link.o counter.o sccp_state.o bsc.o ss7_application.o vty_interface_legacy.o vty_interface_cmds.o mgcp_patch.o mgcp_callagent.o isup_filter.o -ltalloc -losmocore -ltalloc -losmogsm -losmocore -ltalloc -losmovty -losmocore -losmosccp -losmoxua  -lpthread -lnetsnmp -lcrypto
[   79s] /usr/lib/gcc/x86_64-linux-gnu/6/../../../x86_64-linux-gnu/libosmosccp.so: undefined reference to `talloc_free'

Change-Id: I94c87496ebffd41a6217d860b0ca4bed6ff2d24c
diff --git a/src/Makefile.am b/src/Makefile.am
index 2052851..3a006f2 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -17,8 +17,8 @@
 		     mtp_link.c counter.c sccp_state.c bsc.c ss7_application.c \
 		     vty_interface_legacy.c vty_interface_cmds.c mgcp_patch.c \
 		     mgcp_callagent.c  isup_filter.c
-cellmgr_ng_LDADD = $(LIBOSMOCORE_LIBS) $(LIBOSMOGSM_LIBS) $(LIBOSMOVTY_LIBS) \
-		   $(LIBOSMOSCCP_LIBS) $(NEXUSWARE_C7_LIBS) \
+cellmgr_ng_LDADD = $(LIBOSMOSCCP_LIBS) $(LIBOSMOGSM_LIBS) $(LIBOSMOVTY_LIBS) \
+		   $(LIBOSMOCORE_LIBS) $(NEXUSWARE_C7_LIBS) \
 		   -lpthread -lnetsnmp -lcrypto
 
 osmo_stp_SOURCES = main_stp.c mtp_layer3.c thread.c pcap.c link_udp.c snmp_mtp.c \
@@ -28,6 +28,6 @@
 		   vty_interface.c vty_interface_cmds.c mgcp_patch.c \
 		   mgcp_callagent.c isup_filter.c sctp_m3ua_client.c \
 		   sctp_m3ua_misc.c
-osmo_stp_LDADD = $(LIBOSMOCORE_LIBS) $(LIBOSMOGSM_LIBS) $(LIBOSMOVTY_LIBS) \
-		 $(LIBOSMOSCCP_LIBS) $(NEXUSWARE_C7_LIBS) \
+osmo_stp_LDADD = $(LIBOSMOSCCP_LIBS) $(LIBOSMOGSM_LIBS) $(LIBOSMOVTY_LIBS) \
+		 $(LIBOSMOCORE_LIBS) $(NEXUSWARE_C7_LIBS) \
 		   -lpthread -lnetsnmp -lcrypto -lxua -lsctp