tree 73349771435d8bfd85542ab4cc59cd7a2ce86a5b
parent 31b7ba975b55c1ad082c74b02ef8b25701035640
author Yu Shan <shanyu@google.com> 1537311687 -0700
committer Yu Shan <shanyu@google.com> 1537380041 -0700

Clear __USE_FORTIFY_LEVEL after push it to stack.

We need to undefine __USE_FORTIFY_LEVEL when including 'string.h'
after storing the old value to stack. Previously I forget to clean
the value thus __USE_FORTIFY_LEVEL still takes effect.

Tests: Add -O2 -U_FORTIFY_SOURCE -D_FORTIFY_SOURCE=2 -g to
GENERIC_CPPFLAGS in trusty/kernel/make/host_test.mk, make sure
the gcc build passes without error.
Bug: None
Change-Id: Ifa0b7ef20d68ac73113ab787e125631105bf449c