If a local (AF_LOCAL, AF_UNIX) socket creation (bind) is attempted
on a fuse mounted file system, it will crash. Although it may be
possible to make this work correctly, this patch avoids the crash
in the meantime.
I removed the MPASS(), since panicing for the FIFO case didn't make
a lot of sense when it returns an error for the others.

PR: 195000
Submitted by: henry.hu.sh@gmail.com (earlier version)
MFC after: 2 weeks