LU-15984 o2iblnd: debug message is missing a newline

LU-15984 o2iblnd: debug message is missing a newline

Add missing newline to one of the debug messages in
kiblnd_pool_alloc_node.

Test-Parameters: trivial
Signed-off-by: Serguei Smirnov <ssmirnov@whamcloud.com>
Change-Id: I541622322ea6166892270dbfd1567cc64f8c314c
Reviewed-on: https://review.whamcloud.com/47933
Tested-by: jenkins <devops@whamcloud.com>
Reviewed-by: Frank Sehr <fsehr@whamcloud.com>
Reviewed-by: Cyril Bordage <cbordage@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: James Simmons <jsimmons@infradead.org>
Reviewed-by: Oleg Drokin <green@whamcloud.com>