lib/oe/rootfs: fix log_check warnings being printed twice with RPM packaging

lib/oe/rootfs: fix log_check warnings being printed twice with RPM packaging

We were calling _log_check() in the RPM-specific rootfs class as well as
in the base class; this is unnecessary and resulted in any errors/warnings
generated during the actual package installation time triggering two warnings
instead of one. Drop the call from RpmRootfs._create() to fix this.

(From OE-Core rev: 541c56d755ba0354297673e857628026ad9e4df2)

(From OE-Core rev: 9654a6a238a44ed1025a45e4ad1cb779a8684344)

Signed-off-by: Paul Eggleton <paul.eggleton@linux.intel.com>
Signed-off-by: Ross Burton <ross.burton@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
Signed-off-by: Armin Kuster <akuster808@gmail.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>