Avoid conflicts with multiple versions of udev by first trying the library that is linked with the executable, if any, and then picking the one that is in the build environment.

This fixes joystick detection for applications using the Steam Linux Runtime

configure.in

@@ -2231,6 +2231,12 @@ AC_HELP_STRING([--enable-libudev], [enable libudev support [[default=yes]]]),
                         have_libudev_h_hdr=no)
         if test x$have_libudev_h_hdr = xyes; then
             AC_DEFINE(HAVE_LIBUDEV_H, 1, [ ])
+
+            udev_lib=[`find_lib "libudev.so.*" "" | sed 's/.*\/\(.*\)/\1/; q'`]
+            if test x$udev_lib != x; then
+                echo "-- dynamic udev -> $udev_lib"
+                AC_DEFINE_UNQUOTED(SDL_UDEV_DYNAMIC, "$udev_lib", [ ])
+            fi
         fi
     fi
 }