inotify-tools: fix compilation with musl 1.2.4

inotify-tools: fix compilation with musl 1.2.4

Fixes errors in the form of:
inotifytools.c: In function 'inotifytools_watch_recursively_with_exclude':
inotifytools.c:1335:30: error: storage size of 'my_stat' isn't known
 1335 |         static struct stat64 my_stat;
      |                              ^~~~~~~
inotifytools.c:1342:36: error: implicit declaration of function 'lstat64'; did you mean 'lstat'? [-Werror=implicit-function-declaration]
 1342 |                         if ( -1 == lstat64( next_file, &my_stat ) ) {
      |                                    ^~~~~~~
      |                                    lstat
inotifytools.c:1335:30: error: unused variable 'my_stat' [-Werror=unused-variable]
 1335 |         static struct stat64 my_stat;
      |                              ^~~~~~~
inotifytools.c: In function 'isdir':
inotifytools.c:1621:30: error: storage size of 'my_stat' isn't known
 1621 |         static struct stat64 my_stat;
      |                              ^~~~~~~
inotifytools.c:1621:30: error: unused variable 'my_stat' [-Werror=unused-variable]
inotifytools.c:1630:1: error: control reaches end of non-void function [-Werror=return-type]
 1630 | }
      | ^
cc1: all warnings being treated as errors

Signed-off-by: Nick Hainke <vincent@systemli.org>