git: openjdk/jdk: 8266087: Move 'buffer' declaration in get_user_name_slow() inside of linux specific code

[Harold Seigel]

Changeset: f40bf1d2
Author:    Harold Seigel <hseigel at openjdk.org>
Date:      2021-04-28 14:50:12 +0000
URL:       https://git.openjdk.java.net/jdk/commit/f40bf1d24010e3bd9252cef790e9f3039376fb08

8266087: Move 'buffer' declaration in get_user_name_slow() inside of linux specific code

Reviewed-by: zgu, dcubed

! src/hotspot/os/posix/perfMemory_posix.cpp