build: fix shared library dependencies

When --with-shared is specified, we need to make sure the
shared libraries have been built before we start linking
applications.

Signed-off-by: Jim Harris <james.r.harris@intel.com>
Change-Id: I98510b29cca67e09f0c33ac9c8e823e61ac5dc8d

Reviewed-on: https://review.gerrithub.io/424722
Chandler-Test-Pool: SPDK Automated Test System <sys_sgsw@intel.com>
Reviewed-by: Lance Hartmann <lance.hartmann@oracle.com>
Reviewed-by: Ben Walker <benjamin.walker@intel.com>
Reviewed-by: Shuhei Matsumoto <shuhei.matsumoto.xt@hitachi.com>
Tested-by: SPDK CI Jenkins <sys_sgci@intel.com>

Makefile

@@ -52,6 +52,12 @@ endif
 endif
 endif
 
+ifeq ($(CONFIG_SHARED),y)
+LIB = shared_lib
+else
+LIB = lib
+endif
+
 all: $(DIRS-y)
 clean: $(DIRS-y)
 	$(Q)rm -f mk/cc.mk
@@ -62,9 +68,9 @@ install: all
 
 shared_lib: lib
 lib: $(DPDKBUILD)
-app: lib
-test: lib
-examples: lib
+app: $(LIB)
+test: $(LIB)
+examples: $(LIB)
 pkgdep:
 	sh ./scripts/pkgdep.sh