Store USE_DLMALLOC in vppinfra/config.h

Change-Id: Ib596e7f525b83dc7e830bcf6a126cd210216ce86
Signed-off-by: Damjan Marion <damarion@cisco.com>
diff --git a/src/Makefile.am b/src/Makefile.am
index 6a92275..68cff78 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -19,7 +19,7 @@
 ACLOCAL_AMFLAGS = -I m4
 AM_LIBTOOLFLAGS = --quiet
 
-AM_CFLAGS = @CPU_FLAGS@ @DLMALLOC@ -Wall
+AM_CFLAGS = @CPU_FLAGS@ -Wall
 AM_CXXFLAGS = -Wall -std=gnu++11
 
 SUBDIRS = .