Modify number constant 7 to comprehensive macro expression.

Signed-off-by: Jim Huang <jserv@0xlab.org>
test: Fix typo (Ctrl+h)

Signed-off-by: Jim Huang <jserv@0xlab.org>
Let show_commit_string() have the same parameters as other show* functions.

Signed-off-by: Jim Huang <jserv@0xlab.org>