Only put .o files into static libraries when building for the host.

In particular don't put the symbol indices from included .a files into
them. I didn't change the equivalent device rule ala the "if it ain't
broke" rule of thumb.

Change-Id: I064ac356a6f48f93fca2cd08a8408ca835f8f9a4
diff --git a/core/definitions.mk b/core/definitions.mk
index 72e0cb1..a7d5838 100644
--- a/core/definitions.mk
+++ b/core/definitions.mk
@@ -945,7 +945,7 @@
 	rm -rf $$ldir; \
 	mkdir -p $$ldir; \
 	filelist=; \
-	for f in `$(HOST_AR) t $(lib)`; do \
+	for f in `$(HOST_AR) t $(lib) | grep '\.o$$'`; do \
 	    $(HOST_AR) p $(lib) $$f > $$ldir/$$f; \
 	    filelist="$$filelist $$ldir/$$f"; \
 	done ; \