mktime() expects months numbered 0-11

[patatetom]

diff --git a/src/fatxfs_fuse.c b/src/fatxfs_fuse.c
index 9ab8bb6..0dfca51 100644
--- a/src/fatxfs_fuse.c
+++ b/src/fatxfs_fuse.c
@@ -276,7 +276,7 @@ int fatx_fuse_get_attr(const char  *path, struct stat *stbuf)
     timeinfo.tm_min  = attr.modified.minute;
     timeinfo.tm_hour = attr.modified.hour;
     timeinfo.tm_mday = attr.modified.day;
-    timeinfo.tm_mon  = attr.modified.month;
+    timeinfo.tm_mon  = attr.modified.month-1;
     timeinfo.tm_year = attr.modified.year-1900;
     stbuf->st_mtime  = mktime(&timeinfo);