staging: lustre: ptlrpc: convert spaces to tabs

Fix the following type of checkpatch warning to comply with coding
style:
WARNING: please, no spaces at the start of a line

Signed-off-by: Kristina Martsenko <kristina.martsenko@gmail.com>
Reviewed-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>