SUNRPC: Fix validity issues with rpc_pipefs sb->s_fs_info
SUNRPC: Fix validity issues with rpc_pipefs sb->s_fs_info

rpc_kill_sb() must defer calling put_net() until after the notifier
has been called, since most (all?) of the notifier callbacks assume
that sb->s_fs_info points to a valid net namespace. It also must not
call put_net() if the call to rpc_fill_super was unsuccessful.

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=48421

Signed-off-by: Trond Myklebust <6a1f9db795c9fc44be97d66ab114c53193bd3d13@netapp.com>
Cc: Stanislav Kinsbursky <43b28e187c4fe6e53d7ab0bb71957481e322f182@parallels.com>
Cc: 4fbacc2fa0ffdbb11bf1ad6925b886ebd08dd15f@vger.kernel.org [>= v3.4]

KristFoundation/Programs,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas