logrotate: two minor fixes

logrotate: two minor fixes

* Change EXTRA_OEMAKE = "CC='${CC}'" to "", the root cause is the "-e"
  from EXTRA_OEMAKE makes the CFLAGS from the env overrides the one
  defined in logrotate/Makefile which causes build failures, so we need to
  set EXTRA_OEMAKE to "", set it to CC='${CC}' would confuse the user
  since CC='${CC}' has been defined in the env.

* Merge do_install() and do_install_append()

(From OE-Core rev: 692cafa46b37fb15a4397114a8380b35ecc09d7f)

Signed-off-by: Robert Yang <liezhi.yang@windriver.com>
Signed-off-by: Saul Wold <sgw@linux.intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>