t1502: don't create unused files

t1502: don't create unused files

Three tests in file t1502-rev-parse-parseopt.sh use three redirections
with invocation of "git rev-parse --parseopt --".  All three tests
redirect standard output to file "out" and file "spec" to standard
input.  Two of the tests redirect standard output a second time to file
"actual", and the third test redirects standard error to file "err".
These tests check contents of files "actual" and "err", but don't use
the files named "out" for assertions.  The two tests that redirect to
standard output twice might also be confusing to the reader.

Don't redirect standard output of "git rev-parse" to file "out" in
t1502-rev-parse-parseopt.sh to avoid creating unnecessary files.

Acked-by: Øystein Walle <oystwa@gmail.com>
Signed-off-by: Andrei Rybak <rybak.a.v@gmail.com>
Reviewed-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>