[#1632] use literal in AC_CHECK_HEADERS

diff --git a/m4macros/ax_crypto.m4 b/m4macros/ax_crypto.m4
index 9f4ef11926005146c55c023343cb1b5487fd482c..74b4400d980c5f2dca0d8476937ff62429d635df 100644 (file)
--- a/m4macros/ax_crypto.m4
+++ b/m4macros/ax_crypto.m4
@@ -199,14 +199,13 @@ EOF
    # failure handler we can detect the difference between a header not existing
    # (or not even passing the pre-processor phase) and a header file resulting
    # in compilation failures.
-   HEADER_TO_CHECK=botan/botan.h
-   AC_CHECK_HEADERS([${HEADER_TO_CHECK}],,[
+   AC_CHECK_HEADERS([botan/botan.h],,[
         CRYPTO_INCLUDES=""
         CRYPTO_LIBS=""
         CRYPTO_LDFLAGS=""
         CRYPTO_RPATH=""
         if test "x$ac_header_preproc" = "xyes"; then
-                AC_MSG_RESULT([${HEADER_TO_CHECK}
+                AC_MSG_RESULT([botan/botan.h}
 was found but is unusable. The most common cause of this problem
 is attempting to use an updated C++ compiler with older C++ libraries, such as
 the version of Botan that comes with your distribution. If you have updated