Fix dependency issue with vrouter-dpdk

Need to make the .o's of contrail-vrouter-dpdk depend on dpdk_lib,
as they need the .h's of dpdk_lib to compile .c->.o's.

Change-Id: Ia9a81d4745625d71e28f9b7d3758d15b77a4fbe3
Partial-Bug: #1599674

SConscript

@@ -168,7 +168,7 @@ if sys.platform != 'darwin':
 
     for sdir in subdirs:
         env.SConscript(sdir + '/SConscript',
-                       exports=' '.join(exports),
+                       exports = exports,
                        variant_dir = env['TOP'] + '/vrouter/' + sdir,
                        duplicate = 0)
 

dpdk/SConscript

@@ -23,8 +23,9 @@ env.Replace(LIBS = ['dp_core', 'dp_sandesh_c', 'dp_core', 'sandesh-c'])
 env.Append(LIBS = ['rt', 'dl', 'pthread', 'urcu-qsbr'])
 env.Append(LINKFLAGS = env['DPDK_LINKFLAGS'])
 
-dpdk_vrouter = env.Program('contrail-vrouter-dpdk', Glob('*.c'))
-env.Requires(dpdk_vrouter, dpdk_lib)
+dpdk_objs = env.Object(Glob('*.c'))
+dpdk_vrouter = env.Program('contrail-vrouter-dpdk', dpdk_objs)
+env.Requires(dpdk_objs, dpdk_lib)
 
 # to make sure that all are built when you do 'scons' @ the top level
 env.Default(dpdk_vrouter)