Reduce the scope of the vnode lock such that it does not cover the various copyouts associated with initializing the process's argv/env data in userspace.  It is possible that these copyout operations can fault under memory pressure, possibly resulting in dead locks.  This is believed to be safe since none of the copyout_strings() operations need to interact with the vnode here.
Reduce the scope of the vnode lock such that it does not cover
the various copyouts associated with initializing the process's
argv/env data in userspace.  It is possible that these copyout
operations can fault under memory pressure, possibly resulting
in dead locks.  This is believed to be safe since none of the
copyout_strings() operations need to interact with the vnode here.

Submitted by:	Zhouyi Zhou
PR:		kern/111260
Discussed with:	kib
MFC after:	3 weeks

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