configure.ac: typo 'test x=xno' ==> 'test x = xno'

configure.ac

@@ -252,7 +252,7 @@ if test x$enable_cuda = xyes -o x$enable_cuda = xmaybe; then
 			AC_HAVE_LIBRARY([cuda],[found_cudalib=yes],[found_cudalib=no])
 		fi
 
-		if test x$found_cudalib=xno -a -d "$cuda_dir/lib64/"; then
+		if test x$found_cudalib = xno -a -d "$cuda_dir/lib64/"; then
 			LDFLAGS="${SAVED_LDFLAGS} -L$cuda_dir/lib64/ "
 	                STARPU_CUDA_LDFLAGS="-L$cuda_dir/lib64/"
 		fi