Use nodisplay option when performing tests (linux only).

m4/ax_matlab_batch_options.m4

@@ -22,7 +22,13 @@ AC_REQUIRE([AX_MATLAB_ARCH])
 AC_REQUIRE([AX_MATLAB_VERSION])
 
 AX_COMPARE_VERSION([$MATLAB_VERSION], [ge], [9.6],
-  [MATLAB_BATCH_OPTIONS='-noFigureWindows -batch'],
+  [
+    if test "${MATLAB_ARCH}" = win32 -o "${MATLAB_ARCH}" = win64; then
+      MATLAB_BATCH_OPTIONS='-noFigureWindows -batch'
+    else
+      MATLAB_BATCH_OPTIONS='-nodisplay -batch'
+    fi
+  ],
   [
     if test "${MATLAB_ARCH}" = win32 -o "${MATLAB_ARCH}" = win64; then
       MATLAB_BATCH_OPTIONS='-nosplash -automation -wait -sd "$(CURDIR)" -r'