Add missing includes.

Caused warnings about implicitly defined malloc() and sprintf().

Change-Id: Ia56309adc11caf5801ffd88e374c512b785cfd93
diff --git a/libcutils/process_name.c b/libcutils/process_name.c
index b235429..bda9d08 100644
--- a/libcutils/process_name.c
+++ b/libcutils/process_name.c
@@ -14,6 +14,7 @@
  * limitations under the License.
  */
 
+#include <stdlib.h>
 #include <string.h>
 #include <cutils/process_name.h>
 #include <cutils/properties.h>