fix C style comment

diff --git a/acinclude.m4 b/acinclude.m4
index 1875c0d..eb3c245 100644 (file)
--- a/acinclude.m4
+++ b/acinclude.m4
@@ -1468,8 +1468,10 @@ AC_DEFUN([CURL_CHECK_FUNC_CLOCK_GETTIME_MONOTONIC], [
 #endif
     ]],[[
 #if defined(_POSIX_MONOTONIC_CLOCK) && (_POSIX_MONOTONIC_CLOCK > 0)
-      dnl The monotonic clock will not be used unless the feature test macro is
-      dnl defined with a value greater than zero indicating _always_ supported.
+      /*
+      The monotonic clock will not be used unless the feature test macro is
+      defined with a value greater than zero indicating _always_ supported.
+      */
       struct timespec ts;
       (void)clock_gettime(CLOCK_MONOTONIC, &ts);
 #else