Remove runltp-ng symlink from Makefile

Symlinks can be broken when it comes to install runltp-ng using a build
system such as buildroot, because during "make install" we are going to
use absolute paths pointing to the build system insternal folder.

Author: acerv

Makefile

@@ -15,6 +15,4 @@ install:
 	install -m 00644 $(top_srcdir)/tools/runltp-ng/ltp/*.py $(INSTALL_DIR)/ltp
 	install -m 00775 $(top_srcdir)/tools/runltp-ng/runltp-ng $(INSTALL_DIR)/runltp-ng
 
-	ln -sf $(INSTALL_DIR)/runltp-ng $(prefix)/runltp-ng
-
 include $(top_srcdir)/include/mk/generic_leaf_target.mk