Remove pragma ident lines

The #pragma ident is a historical relic and not needed any more, this
pragma is actually unknown for common compilers and is only causing
trouble.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Matt Macy <mmacy@FreeBSD.org>
Signed-off-by: Toomas Soome <tsoome@me.com>
Closes #10810