smbfs: remove duplicated #include

Remove duplicated #include('s) in fs/smbfs/symlink.c

Signed-off-by: Huang Weiyi <weiyi.huang@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>