Make two style changes to create new commit and document proper commit
message for r185765.

Noted by: rdivacky
Requested by: des

Commit message for r185765 should be:
In procfs map handler, and in linprocfs maps handler, do not call
vn_fullpath() while having vm map locked. This is done in anticipation
of the vop_vptocnp commit, that would make vn_fullpath sometime
acquire vnode lock.

Also, in linprocfs, maps handler already acquires vnode lock.

No objections from: des
MFC after: 2 week