format string as ("%s", buf) instead of (buf)
format string as ("%s", buf) instead of (buf)

To avoid compiler warnings (when enabled) such as:
format not a string literal and no format arguments [-Werror=format-security]

Signed-off-by: David Butterfield <a9fc080b52063dba1f42b7aaa6b29e259d2b7ea9@wdc.com>

open-iscsi/tcmu-runner,open-iscsi/tcmu-runner,agrover/tcmu-runner