fuse: make nargv a stack variable
fuse: make nargv a stack variable

Don't unnecessarily malloc nargv, when we know its size in advance.

Signed-off-by: Ramkumar Ramachandra <5c355d1d38066ed0c5de420d67c1b5ed0687c4bd@gmail.com>

artagnon/phoenixfs,artagnon/phoenixfs,artagnon/phoenixfs