random: fix up sparse warnings

Add extern and static declarations to suppress sparse warnings

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
FS: import F2FS

Signed-off-by: flar2 <asegaert@gmail.com>
Merge branch 'origin/cm-11.0'
: flar2 <asegaert@gmail.com>