build: fix distcheck

[Akim Demaille]

commit 0782ed327401d1b59c059c89c8630d002260b4f7
Author: Akim Demaille <address@hidden>
Date:   Sat Feb 16 14:21:36 2019 +0100

    build: fix distcheck
    
    Regression introduced in 05a80977798abf472bfc11c477751303ad604733.
    
    * doc/local.mk (bison.help): Don't depend on the path of the bison
    executable.

diff --git a/doc/local.mk b/doc/local.mk
index 8959877d..d56290e4 100644
--- a/doc/local.mk
+++ b/doc/local.mk
@@ -90,9 +90,11 @@ MAINTAINERCLEANFILES += $(top_srcdir)/doc/bison.help
 $(top_srcdir)/doc/bison.help: src/bison$(EXEEXT)
        $(AM_V_GEN)LC_ALL=C tests/bison --version >doc/bison.help.tmp
        $(AM_V_at) LC_ALL=C tests/bison --help | \
+## Avoid depending on the path to Bison.
+         sed -e 's,^Usage: .*/bison \[OPTION\],Usage: bison [OPTION],g' \
 ## Avoid variations in the output depending on whether we are
 ## on a glibc system.
-         sed '/translation bugs/d'  >>doc/bison.help.tmp
+             -e '/translation bugs/d'  >>doc/bison.help.tmp
        $(AM_V_at)$(top_srcdir)/build-aux/move-if-change doc/bison.help.tmp $@
 endif ! CROSS_COMPILING