MFC r273107:

Make automount(8)/automountd(8) treat percent sign as a valid part
of path.  It's useful for spaces encoded as %20 as msdosfs labels.

Submitted by:	glebius@
MFC r272717:

Remove call to access(2) which didn't serve any purpose, and make it more
tolerant to errors.

Sponsored by:	The FreeBSD Foundation