LU-14093 utils: fix format-overflow warning

LU-14093 utils: fix format-overflow warning

Fix the following warning on gcc11 by making numbuf big enough to fit
format content.

lfs.c: In function ‘print_quota’:
lfs.c:7719:48: error: ‘sprintf’ may write a terminating nul past the end of the destination [-Werror=format-overflow=]
 7719 |                         sprintf(numbuf[0], "%s*", strbuf);
      |                                                ^
lfs.c:7719:25: note: ‘sprintf’ output between 2 and 33 bytes into a destination of size 32
 7719 |                         sprintf(numbuf[0], "%s*", strbuf);
      |                         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Test-parameters: trivial

Lustre-change: https://review.whamcloud.com/43711
Lustre-commit: a0fe9be254b944f5b005dd4b36c414827bcb40df

Change-Id: I021e6ffff2e1405eadbe689f718674af4d4d6376
Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>
Reviewed-on: https://review.whamcloud.com/46212
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>