tools: Remove unecessary symlinking of zlib.h

crc32.c uses the zlib.h header in include/u-boot/zlib.h.  The symlink
was previously necessary to give U-Boot's version of zlib.h precedence
over the host computer's version of zlib.h.

Signed-off-by: Peter Tyser <ptyser@xes-inc.com>
diff --git a/tools/.gitignore b/tools/.gitignore
index 377ca9a..c2ac0ae 100644
--- a/tools/.gitignore
+++ b/tools/.gitignore
@@ -18,4 +18,3 @@
 /fdt_strerror.c
 /fdt_wip.c
 /libfdt_internal.h
-/zlib.h
diff --git a/tools/Makefile b/tools/Makefile
index e1f262b..037f61b 100644
--- a/tools/Makefile
+++ b/tools/Makefile
@@ -258,11 +258,7 @@
 $(obj)env_embedded.o:	$(obj)env_embedded.c
 	$(CC) -g $(HOST_ENVIRO_CFLAGS) $(CPPFLAGS) -c -o $@ $<
 
-$(obj)zlib.h:
-	@rm -f $@
-	ln -s $(src)../include/zlib.h $@
-
-$(obj)crc32.c: $(obj)zlib.h
+$(obj)crc32.c: $(SRCTREE)/include/u-boot/zlib.h
 	@rm -f $(obj)crc32.c
 	ln -s $(src)../lib_generic/crc32.c $(obj)crc32.c