Bypass alias for grep in the tapas command.

Change-Id: I82705535bda927ddc7e9aebb9610d712b68a50d2
diff --git a/core/definitions.mk b/core/definitions.mk
index 5410b11..57201c0 100644
--- a/core/definitions.mk
+++ b/core/definitions.mk
@@ -1104,7 +1104,7 @@
     rm -rf $$ldir; \
     mkdir -p $$ldir; \
     filelist=; \
-    for f in `$(HOST_AR) t $(1) | grep '\.o$$'`; do \
+    for f in `$(HOST_AR) t $(1) | \grep '\.o$$'`; do \
         $(HOST_AR) p $(1) $$f > $$ldir/$$f; \
         filelist="$$filelist $$ldir/$$f"; \
     done ; \