Documentation: filesystems: fix two misspells

This fixes two small misspells in the filesystems documentation.

Signed-off-by: Bingwu Zhang <[e-mail]>
Reviewed-by: Darrick J. Wong <[e-mail]>
Signed-off-by: Jonathan Corbet <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]

Documentation/filesystems/iomap/operations.rst

···
 
     For the pagecache, races can happen if writeback doesn't take
     ``i_rwsem`` or ``invalidate_lock`` and updates mapping information.
-    Races can also happen if the filesytem allows concurrent writes.
+    Races can also happen if the filesystem allows concurrent writes.
     For such files, the mapping *must* be revalidated after the folio
     lock has been taken so that iomap can manage the folio correctly.
 

Documentation/filesystems/overlayfs.rst

···
 to "y".  Where the upper filesystem contains an opaque directory, any
 directory in the lower filesystem with the same name is ignored.
 
-An opaque directory should not conntain any whiteouts, because they do not
+An opaque directory should not contain any whiteouts, because they do not
 serve any purpose.  A merge directory containing regular files with the xattr
 "trusted.overlay.whiteout", should be additionally marked by setting the xattr
 "trusted.overlay.opaque" to "x" on the merge directory itself.