Fix wrong constant names to create version number

Thanks to Denis Davydov

src/modbus-version.h.in

@@ -35,9 +35,9 @@
 #define LIBMODBUS_VERSION_STRING "@LIBMODBUS_VERSION@"
 
 /* Numerically encoded version, like 0x010203 */
-#define LIBMODBUS_VERSION_HEX ((LIBMODBUS_MAJOR_VERSION << 24) |        \
-                               (LIBMODBUS_MINOR_VERSION << 16) |        \
-                               (LIBMODBUS_MICRO_VERSION << 8))
+#define LIBMODBUS_VERSION_HEX ((LIBMODBUS_VERSION_MAJOR << 24) |  \
+                               (LIBMODBUS_VERSION_MINOR << 16) |  \
+                               (LIBMODBUS_VERSION_MICRO << 8))
 
 /* Evaluates to True if the version is greater than @major, @minor and @micro
  */

tests/version.c

@@ -20,7 +20,7 @@
 
 int main(void)
 {
-    printf("Compiled with libmodbus version %s\n", LIBMODBUS_VERSION_STRING);
+    printf("Compiled with libmodbus version %s (%08X)\n", LIBMODBUS_VERSION_STRING, LIBMODBUS_VERSION_HEX);
     printf("Linked with libmodbus version %d.%d.%d\n",
            libmodbus_version_major, libmodbus_version_minor, libmodbus_version_micro);