https://github.com/LudovicRousseau/PCSC/commit/a4bdfd2eb6e908c8306fe421137a83573ba05d8c
https://bugs.gentoo.org/832593

From: Fabrice Fontaine <fontaine.fabrice@gmail.com>
Date: Tue, 14 Dec 2021 08:20:59 +0100
Subject: [PATCH] src/hotplug_generic.c: fix build without lib{udev,usb}

Fix the following build failure without lib{udev,usb} raised since
version 1.9.5 and
https://github.com/LudovicRousseau/PCSC/commit/6f8f170db3c88c59a5ddb5ae5319b921a901a6aa:

/home/giuliobenetti/autobuild/run/instance-2/output-1/host/lib/gcc/arm-buildroot-linux-gnueabihf/11.2.0/../../../../arm-buildroot-linux-gnueabihf/bin/ld: pcscd-pcscdaemon.o: in function `signal_thread':
pcscdaemon.c:(.text+0x444): undefined reference to `HPReCheckSerialReaders'

Fixes:
 - http://autobuild.buildroot.org/results/6cf323229f32967aa554418410dc94b7094d09af

Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
--- a/src/hotplug_generic.c
+++ b/src/hotplug_generic.c
@@ -48,7 +48,7 @@ THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 #define FALSE 0
 #endif
 
-#if !defined(__APPLE__) && !defined(HAVE_LIBUSB) && !defined(__linux__) && !defined(HAVE_LIBUDEV)
+#if !defined(__APPLE__) && !defined(HAVE_LIBUSB) && !defined(HAVE_LIBUDEV)
 
 LONG HPSearchHotPluggables(void)
 {