joystick: hidapi: Properly include <unistd.h> when inotify not available

In the extremely unlikely event that inotify is not available (and,
therefore, HAVE_INOTIFY is not #defined), SDL will no-longer build.

This is because <unistd.h> is only included when HAVE_INOTIFY is
defined, and PR #4098 adds a call to access(…, F_OK), which requires
<unistd.h>.

(Note that the F_OK symbol is the only one which actually prevented
SDL from compiling, but both access() and close() fell back to implicit
definitions, which is a bit concerning.)

Fixes: 8d43f45a7b ("Don't use udev for joystick enumeration if running in a container")

src/joystick/hidapi/SDL_hidapijoystick.c

@@ -57,8 +57,8 @@
 #include <fcntl.h>
 #include <limits.h>             /* For the definition of NAME_MAX */
 #include <sys/inotify.h>
-#include <unistd.h>
 #endif
+#include <unistd.h>
 #endif
 
 typedef enum