DELETEF loses when LIB: used

[DAVE.TOURETZKY at CMU-10A]

TOPS-10 allows users to set a pseudo-device called LIB: to point to
an arbitrary account.  File lookups that fail for the user's directory
are tried on LIB: before giving up.  This is a useful feature; I often
set my LIB: to C380ML5P (the MacLisp account) to run NEWLSP quicker.

However, DELETEF appears to also be using the LIB: lookup option, and
thus bombing with a protection failure whenever I delete a non-existent
file that does happen to exist on the LIB: account.  This happens more
frequently than you might think, as COMPLR tries to delete .FAS files
while compiling.  If I have no .FAS file, but one does exist on
C380ML5P, it flames out.

It is possible to not use the LIB: lookup when seeking a file; PIP does
so (and thus so does the TOPS-10 DELETE command.)  MacLisp should do
likewise.