[gnumeric] configure: with --with-long-double

[Morten Welinder <mortenw src gnome org>]

commit 29a296c604e4174b8fa404e46a8cf5cf10389529
Author: Morten Welinder <terra gnome org>
Date:   Sun Sep 19 11:07:17 2021 -0400

    configure: with --with-long-double

 NEWS         | 3 +++
 configure.ac | 4 ++--
 2 files changed, 5 insertions(+), 2 deletions(-)
---
diff --git a/NEWS b/NEWS
index 2055a4805..ae97c2e2d 100644
--- a/NEWS
+++ b/NEWS
@@ -3,6 +3,9 @@ Gnumeric 1.12.51
 Jean:
        * Fix error bars when data are in a multi-column array. [#594]
 
+Morten:
+       * Fix --with-long-double configuration.
+
 --------------------------------------------------------------------------
 Gnumeric 1.12.50
 
diff --git a/configure.ac b/configure.ac
index e007d9e21..4b1717851 100644
--- a/configure.ac
+++ b/configure.ac
@@ -668,12 +668,12 @@ AC_ARG_WITH(long_double,
                        have_erfcl=$ac_cv_func_erfcl
                        ])
 
-               if $have_erfl = no; then
+               if test $have_erfl = no; then
                        AC_DEFINE(GNM_SUPPLIES_ERFL, 1,
                                 [Define if Gnumeric supplies the erfl function]
                                 )
                fi
-               if $have_erfcl = no; then
+               if test $have_erfcl = no; then
                        AC_DEFINE(GNM_SUPPLIES_ERFCL, 1,
                                 [Define if Gnumeric supplies the erfcl function]
                                 )