rpm: remove .real hacks in argument parsing

The argument parser in RPM was patched to look for <binary>.real, but since the
wrapper now fakes the right argv[0] rpm wasn't able to parse any options.

(From OE-Core rev: a67b4cfc41819ed77ed2bc4246228e9d006a4317)

Signed-off-by: Ross Burton <ross.burton@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>