Fix top(1) SIGPIPE behavior.

Bug: 14166609
Change-Id: I4aad1e0db2e875735405d094fb0d1a36862b5b19
diff --git a/toolbox/Android.mk b/toolbox/Android.mk
index 3deb3e7..5383b83 100644
--- a/toolbox/Android.mk
+++ b/toolbox/Android.mk
@@ -95,6 +95,7 @@
 LOCAL_C_INCLUDES := bionic/libc/bionic
 
 LOCAL_CFLAGS += \
+    -std=gnu99 \
     -Wno-unused-parameter \
     -include bsd-compatibility.h \