Disk (Android): fix build

Android does support `statx`, but it requires targeting newer ANDROID_API version to be available

CMakeLists.txt

@@ -699,7 +699,9 @@ check_function_exists(wcwidth HAVE_WCWIDTH)
 if(NOT HAVE_WCWIDTH)
     list(APPEND LIBFASTFETCH_SRC src/3rdparty/mk_wcwidch/wcwidth.c)
 endif()
-check_function_exists(statx HAVE_STATX)
+if(LINUX)
+    check_function_exists(statx HAVE_STATX)
+endif()
 
 if(ENABLE_SYSTEM_YYJSON)
     find_package(yyjson)