[RFA/testsuite] Shorten the maint.exp symbols tests

[David Carlton]

The maint.exp changes in question cause testsuite failures on my
system for 'maint print symbols' and 'maint print psymbols'.  I've
played around with it a bit; it seems to me that if I do

(gdb) maint print symbols symbols_output ./gdb.base/break.c

(which is what maint.exp does in my situation) then I get an empty
file symbols_output, whereas if I just do

(gdb) maint print symbols symbols_output gdb.base/break.c

then I get the correct symbols_output file.  Here, I'm running GDB
from within the testsuite directory; I don't use a separate build
directory when configuring GDB, which might or might not make a
difference.

David Carlton
carlton@math.stanford.edu