Switch to check_symbol_exists() in simplest cases

There are a few exceptions. Some require _GNU_SOURCE, some are in the
weird strings.h header, some are probably too new to be found in the
standard locations.

Fixes #1077

1 files changed, 1 insertions, 1 deletions

diff --git a/apps/nc/CMakeLists.txt b/apps/nc/CMakeLists.txt
index 7bbdb02..d5f7813 100644
--- a/apps/nc/CMakeLists.txt
+++ b/apps/nc/CMakeLists.txt
@@ -22,7 +22,7 @@ else()
         set(NC_SRC ${NC_SRC} compat/accept4.c)
 endif()
 
-check_function_exists(readpassphrase HAVE_READPASSPHRASE)
+check_symbol_exists(readpassphrase "readpassphrase.h" HAVE_READPASSPHRASE)
 if(HAVE_READPASSPHRASE)
         add_definitions(-DHAVE_READPASSPHRASE)
 else()