vvfat: Fix potential buffer overflow

path2[PATH_MAX] can be used for the null termination, so make the array big
enough to allow this.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
diff --git a/block/vvfat.c b/block/vvfat.c
index ba207e2..7e9e35a 100644
--- a/block/vvfat.c
+++ b/block/vvfat.c
@@ -1690,7 +1690,7 @@
 
     long_file_name lfn;
     int path_len = strlen(path);
-    char path2[PATH_MAX];
+    char path2[PATH_MAX + 1];
 
     assert(path_len < PATH_MAX); /* len was tested before! */
     pstrcpy(path2, sizeof(path2), path);