genvers: Use printf instead of echo -n
genvers: Use printf instead of echo -n

Echo -n in MacOS X doesn't work like other platforms.
This commit changes the invocations of echo to printf.

Signed-off-by: Katsuyuki TATEISHI <3553b226127e0cccd2bec8c74a70f7d1603f41f9@wheel.jp>

ktateish/bshtap