build: treat securetransport and schannel like other autodetected libraries

configure

@@ -3606,6 +3606,7 @@ enable_weak cuda cuvid nvenc vda_framework videotoolbox videotoolbox_encoder
 enable_weak zlib bzlib lzma
 
 enable_weak iconv
+enable_weak securetransport schannel
 
 disabled logging && logfile=/dev/null
 
@@ -6055,11 +6056,16 @@ if enabled decklink; then
     esac
 fi
 
-disabled securetransport || { check_func SecIdentityCreate "-Wl,-framework,CoreFoundation -Wl,-framework,Security" &&
-    check_lib securetransport "Security/SecureTransport.h Security/Security.h" "SSLCreateContext SecItemImport" "-Wl,-framework,CoreFoundation -Wl,-framework,Security"; }
+enabled securetransport &&
+    check_func SecIdentityCreate "-Wl,-framework,CoreFoundation -Wl,-framework,Security" &&
+    check_lib securetransport "Security/SecureTransport.h Security/Security.h" "SSLCreateContext SecItemImport" "-Wl,-framework,CoreFoundation -Wl,-framework,Security" ||
+        disable securetransport
 
-disabled schannel || { check_func_headers "windows.h security.h" InitializeSecurityContext -DSECURITY_WIN32 -lsecur32 &&
-                       check_cpp_condition winerror.h "defined(SEC_I_CONTEXT_EXPIRED)" && enable schannel && add_extralibs -lsecur32; }
+enabled schannel &&
+    check_func_headers "windows.h security.h" InitializeSecurityContext -DSECURITY_WIN32 -lsecur32 &&
+    check_cpp_condition winerror.h "defined(SEC_I_CONTEXT_EXPIRED)" &&
+    add_extralibs -lsecur32 ||
+        disable schannel
 
 makeinfo --version > /dev/null 2>&1 && enable makeinfo  || disable makeinfo
 enabled makeinfo \