acinclude.m4: Avoid echo -n
n option for echo is not portable.  Use printf instead.
This fixes OSX build on travis-ci.
Acked-by: Ben Pfaff
@@ -968,7 +968,7 @@ dnl ctags ignores symbols with extras identifiers. This builds a list of
dnl specially handled identifiers to be ignored.
AC_DEFUN([OVS_CTAGS_IDENTIFIERS],
AC_SUBST([OVS_CTAGS_IDENTIFIERS_LIST],
- [`echo -n '-I "'; sed -n 's/^#define \(OVS_[A-Z_]\+\)(\.\.\.)$/\1+/p' ${srcdir}/include/openvswitch/compiler.h | tr \\\n ' ' ; echo -n '"'`] ))
+ [`printf '-I "'; sed -n 's/^#define \(OVS_[A-Z_]\+\)(\.\.\.)$/\1+/p' ${srcdir}/include/openvswitch/compiler.h | tr \\\n ' ' ; printf '"'`] ))
dnl OVS_PTHREAD_SET_NAME
dnl
