pipe-filter-gi, pipe-filter-ii: fix gcc warning

[Bruno Haible]

On mingw, I'm seeing this warning:

In file included from pipe-filter-ii.c:163:0:
pipe-filter-aux.h:75:0: warning: "read" redefined
 #define read nonintr_read
 
In file included from ./fcntl.h:67:0,
                 from pipe-filter-ii.c:23:
./unistd.h:1785:0: note: this is the location of the previous definition
 #   define read rpl_read

This patch should fix the warning.


2019-04-26  Bruno Haible  <address@hidden>

        pipe-filter-gi, pipe-filter-ii: Fix gcc warning.
        * lib/pipe-filter-aux.h (read): Undefine before redefinition.

diff --git a/lib/pipe-filter-aux.h b/lib/pipe-filter-aux.h
index f7e8689..4b33322 100644
--- a/lib/pipe-filter-aux.h
+++ b/lib/pipe-filter-aux.h
@@ -72,6 +72,7 @@ nonintr_read (int fd, void *buf, size_t count)
 
   return retval;
 }
+#undef read /* avoid warning related to gnulib module unistd */
 #define read nonintr_read
 
 PIPE_FILTER_AUX_INLINE ssize_t