test.c: Conditionally do not declare stuff that's in other places
test.c: Conditionally do not declare stuff that's in other places

test.c duplicates a couple of objects (StrnCmp, StrCmp) that are
in libefi.a, as well as SHIM_LOCK_GUID from lib/guid.o.  While it's nice
to have these at some places, we need to disable them if we're actually
linking a test case against either of those.

This patch adds HAVE_foo guards around those objects.

Signed-off-by: Peter Jones <2e0a021e603479ff81838c00c3b770daca4e0214@redhat.com>

rhinstaller/shim,rhinstaller/shim,rhinstaller/shim