fix bug in 'defaultweight' calculation on OSD start.

  awk: cmd. line:1: { d=$2/1073741824 ; r = sprintf(\"%.2f\", d); print r }
  awk: cmd. line:1:                                 ^ backslash not last character on line
  awk: cmd. line:1: { d=$2/1073741824 ; r = sprintf(\"%.2f\", d); print r }
  awk: cmd. line:1:                                 ^ syntax error

Signed-off-by: Dmitry Smirnov <onlyjob@member.fsf.org>
Merge pull request #1530 from onlyjob/fix-defaultweight

fix bug in 'defaultweight' calculation on OSD start.

Reviewed-by: Sage Weil <sage@inktank.com>